Safety Standards for Underground Coal Mine Ventilation

SUMMARY: This final rule revises the Mine Safety and Health

Administration's (MSHA's) existing safety standards for ventilation of

underground coal mines. After publication of the existing standards,

the U.S. Court of Appeals in the D.C. Circuit stayed the application of

one standard and MSHA stayed two standards. The rule revises these

stayed provisions, revises or clarifies other provisions in the rule

and includes some new provisions. The provisions of the final rule are

expected to decrease the potential for fatalities, particularly

accidents which can result in multiple deaths, and to reduce the risk

of injuries and illnesses in underground coal mines. For the

convenience of the reader, MSHA has published the full text of the

ventilation standards for underground coal mines in this document.

EFFECTIVE DATE: The final rule is effective June 10, 1996.

FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey, Director, Office

of Standards, Regulations and Variances, MSHA, phone 703/ 235-1910; fax

703/235-5551.

SUPPLEMENTARY INFORMATION:

I. Background

The mining of coal underground has historically been recognized as

one of the more hazardous occupations in the world. It is a universally

recognized principle of underground coal mine safety that there must be

proper ventilation of the mine. Indeed, no aspect of safety in

underground coal mining is more fundamental than proper ventilation. A

basic tenet of mining safety states that ventilation must be

sufficient: (1) To dilute, render harmless and carry away the hazardous

components of mine air, such as potentially explosive methane; and (2)

to provide necessary levels of oxygen to the miners' working

environment. Ventilation safety programs are designed around this

philosophy. The history of mining is replete with tragic incidents

where one aspect or another of a necessary ventilation safety

protection was either not in place or not followed, with disastrous

results. Examples include the explosion at the Monogah mine in 1907 in

which 362 miners perished, the worst mining disaster in the history of

the United States. Other more recent examples include the Farmington

disaster in 1968 in which 78 miners died, the Scotia mine in 1976 where

26 died, Grundy No. 17 in 1981 where 13 died, Wilberg in 1984 where 27

died, Pyro in 1989 with 10 deaths and Southmountain in 1992 where 8

miners died. In 1969 and again in 1977, Congress recognized the hazards

of improper ventilation and established a role for the government in

addressing ventilation hazards. MSHA, with the cooperation of labor and

industry, has met with a large measure of success in reducing the

accidents, injuries and fatalities that have resulted from poor

ventilation practices. For example, explosions and fires in a 29 year

period from 1940 to 1968 resulted in the deaths of 491 miners. Since

the passage of the Federal Coal Mine Health and Safety Act of 1969, 178

explosion and fire related deaths have occurred. While MSHA recognizes

that this number is still unacceptable, the significant reduction in

loss of life cannot be ignored. To a great extent, the framework for

this success has been the implementation of effective ventilation

standards.

Preventing recurrence of disasters like those of the past remains

the top priority of MSHA. MSHA believes that a serious commitment by

management, labor, and government is necessary to develop effective,

yet reasonable and practical regulations that protect the safety and

health of our nation's miners. MSHA anticipates that this rulemaking,

which revises portions of the comprehensive ventilation rule published

in 1992 (57 FR 20868, May 15, 1992) and adds new provisions, will bring

the coal mining industry closer to that objective.

The comprehensive 1992 ventilation rulemaking was closely followed

by interested industry and labor groups, who frequently expressed

divergent views on approaches to resolving ventilation issues. Certain

commenters exercised their right to challenge the rule and the U.S.

Court of Appeals for the D.C. Circuit Court stayed one provision

relating to oxygen and carbon dioxide in the bleeder entries. MSHA held

a series of informational meetings around the country during which it

explained the application of the rule. In so doing, MSHA listened to

many questions about the implementation of the rule. MSHA was sensitive

to the views expressed at these meetings and gave serious consideration

to these issues. Some of these comments became the basis for portions

of this rulemaking. Internal discussions of MSHA's experience with the

implementation of the rule led MSHA to include still other issues in

this rulemaking. In fact, MSHA stayed the application of two additional

provisions in response to potential problems pointed out by interested

parties. These stayed provisions relate to actions following the

stoppage of the main mine fan with persons underground and to a

potential fire hazard from the enclosure of compressors in a

noncombustible structure. MSHA addresses these issues in the

rulemaking. Once MSHA decided that it was going to proceed with a

rulemaking to address these issues, it added other provisions to the

package to allow all parties an opportunity to comment where they

expressed the view that they had insufficient opportunity to comment on

the existing rule (The comprehensive rule that was published in the

Federal Register on May 15, 1992). The rule MSHA proposed also included

issues raised by parties in litigation challenging the existing rule.

MSHA anticipates that the final rule should resolve matters included in

the challenge raised by the litigation of the existing rule. Finally,

in an effort to address confusion that seemed to exist with certain

provisions of the existing ventilation rule promulgated in May of 1992,

MSHA either proposed clarifications to the existing rule or discussed

the affected provisions in the preambles to the proposed and final

rules in an effort to clarify them.

The issues in the rulemaking are complex and highly technical.

Comments to the proposal (published on May 19, 1994, 59 FR 26536) and

comments following the public hearings (held in September and October

1994, in Price, Utah, Logan, West Virginia, and Washington,

Pennsylvania) were extensive. One party alone submitted over two

thousand pages of written comments and over 275 exhibits. Not only were

the safety issues involved complex, but in many cases, MSHA's task was

made more difficult by hearing diametrically opposed viewpoints.

Major Improvements in the Final Rule

The final rule provides a number of significant improvements to the

existing ventilation regulations. For example, the final rule provides

for the electronic storage of records. A major portion of the mining

industry has this capability at the present time through computer

technology at the mine site. Electronic

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record retention can reduce the cost of storage and maintenance of

records and provide for ease in access and transfer of information

without reducing the protection afforded miners. Additionally, having

records electronically stored can facilitate trend analysis, allowing

for earlier detection and correction of potential hazards.

The final rule also requires pressure recorders or an option of the

use of a fan monitoring system on main mine fans at all mines. This

represents a major step toward monitoring the mine fans controlling the

ventilation at the mines and helps assure that the miners have

uncontaminated air at all times. The final rule also provides for

methane testing at the face during mining operations. This technology

is especially useful for taking methane tests during extended cut

mining operations. The methane testing evaluates air flow to the face

to determine that methane is sufficiently diluted, rendered harmless,

and carried away so as to reduce or eliminate the hazards associated

with methane liberated during mining operations.

Other improvements in the rule include revisions to the three

stayed provisions in the existing rule. Air quality levels for oxygen

and carbon dioxide in bleeders are established to protect mine

examiners who are required to travel to determine if the bleeders are

functioning properly. A second stayed provision is revised to limit the

use of transportation equipment during the withdrawal of miners after

an unintentional fan stoppage. This revision to the existing rule

reduces the likelihood of an ignition from methane that can accumulate

during the fan stoppage. The third stayed provision is revised to allow

the option of attending rather than housing compressors in a

noncombustible enclosure. The hazards associated with the operation of

compressors in underground mines were demonstrated at the Wilberg mine

disaster, where 27 people lost their lives as a result of a compressor

fire.

This final rule provides for an alert and alarm device to be

located outside of noncombustible structures housing electrical

installations. The alert and alarm assures that miners are made aware

of a problem in time to extinguish a fire or safely evacuate an area or

the mine as necessary for safety. Another change to the existing rule

involves miners or their representatives in the mine ventilation plan

approval process before the plan is submitted for approval. This

provides for the opportunity for input from those having first hand

knowledge in the particular mining conditions and practices that impact

the plan approval.

Other safety enhancements from the existing rule include: requiring

the use of extendable probes to conduct methane tests at deep cuts;

requiring on-shift examinations on other than coal producing shifts;

and accepting a performance test to determine minimum dimensions at

certain locations in escapeways.

Finally, the final rule clarifies existing regulations that were

considered vague by some parties or were misunderstood. For example,

the final rule provides that certified pumpers can conduct their own

examination rather than requiring the examination to be conducted

during the preshift segment of the mining operation.

To serve the interests of the mining community, MSHA has

republished the full text of subpart D of 30 CFR part 75 as it will

read upon promulgation of this rule.

II. Discussion of the Final Rule

A. General Discussion

In developing the final rule, MSHA has made every effort to address

the comments received during the rulemaking, and to develop practical

requirements for real safety problems. Both the costs and the benefits

of each standard were also considered. In addition, each standard, as

well as revisions and deletions, was carefully considered against the

statutory requirement that nothing in the final rule shall reduce the

protection afforded miners by an existing mandatory health or safety

standard. Where appropriate, MSHA has provided for a phase in period to

allow mine operators time to effectively plan and implement the

necessary changes.

MSHA carefully analyzed the comments received and responded in many

instances by revising the proposed requirements. For example, unlike

the proposal, the final rule does not require the second level

countersigning of records; allows the use of nonpermissible equipment

when conducting an examination upon restart of a fan following

unintentional fan stoppages, and requires pressure recording devices or

an option of the use of a fan monitoring system to be used on all main

mine fans.

Several commenters strongly urged MSHA to proceed in this

rulemaking on the issue of using air coursed through the belt entries

(``belt air'') to ventilate the working face. MSHA has completed its

consideration of the Report of the Secretary's Advisory Committee

Report on Belt Air and has placed the issue of using belt air to

ventilate the working face on the rulemaking agenda for development of

a proposed rule. Thus, ``belt air'' is not addressed in this

rulemaking.

MSHA has also received comments and recommendations on a number of

other issues that are outside the scope of this rulemaking. For

example, much of the extensive testimony directed toward the use of

atmospheric monitoring systems was beyond the issues dealt with in this

rulemaking. Also, recommendations for the use of transparent or

translucent material for check curtains exceed the scope of this

rulemaking. The final rule, therefore, does not include these

recommendations.

Commenters to the proposal frequently included a discussion of

various accident reports, most written by MSHA. In addition, there were

discussions of other documents related to specific incidents or mines,

such as MSHA Internal Review Reports or specific mine plans. In some

cases, the documents were submitted for inclusion in the record. In

other cases, the documents were merely referenced.

MSHA is independently aware of the extensive history of ventilation

related explosions, and has considered this information. Where

appropriate, this information is discussed in the section-by-section

analysis in the preamble of this rule. MSHA is aware that accidents can

result from or be contributed to by the violation of one or more of the

existing standards. In that context, MSHA has found that the solution

is not necessarily to promulgate another standard. (The offender may be

as likely to ignore it as well.) Instead, for demonstrated

noncompliance with existing standards, the solution is often found in

increased emphasis, training, or enforcement, rather than in the

promulgation of additional rules.

Several sections of the final rule deal with requirements for

sections and areas where mechanized mining equipment is being installed

or removed. These provisions, which were included in the existing

standard published in May 1992, were reproposed without change for the

purpose of receiving additional comments from all interested parties.

One commenter cited the William Station mine explosion as evidence of

the need for these requirements. Other commenters reiterated an earlier

objection that the standards were procedurally flawed. MSHA does not

agree that these provisions are procedurally flawed and notes that each

of these standards was reproposed and not simply restated as part of

this rulemaking. Comments relative to the

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technical merits of an individual standard are addressed in the

section-by-section portion of this preamble.

Recordkeeping Requirements in the Final Rule

The final rule revises the recordkeeping requirements for several

standards. The standards affected are Sec. 75.310, Installation of main

mine fans; Sec. 75.312, Main mine fan examinations and records;

Sec. 75.342, Methane monitors; Sec. 75.360, Preshift examination;

Sec. 75.362, On-shift examination; Sec. 75.363, Hazardous conditions;

posting, correcting and recording; Sec. 75.364, Weekly examinations;

and Sec. 75.370, Mine ventilation plan; contents.

Generally, the final rule requires examiners to record the results

of methane tests as a percent of methane detected; records must be made

in a book that is secure and not susceptible to alteration, or

electronically in such a manner as to be secure and not susceptible to

alteration; and records must be countersigned by the mine foreman by

the end of the mine foreman's next regularly scheduled working shift.

These rules are intended to assure that examination results are

maintained and made available, and that the appropriate level of mine

management is made aware of conditions or problems requiring attention.

The revisions also help assure the integrity of records and enable mine

management to review the quality of the examinations. MSHA intends the

term ``secure and not susceptible to alteration'' when applied to

electronic storage to mean that the stored record cannot be modified.

One example of acceptable storage would be a ``write once, read many''

drive.

Numerous comments were received both supporting and opposing the

proposed recordkeeping requirements. MSHA reviewed and fully considered

each of these comments. The proposal would have required that records

be kept in either state-approved books or in bound books with

sequential machine-numbered pages. Commenters argued that under the

existing rule records may be falsified or altered. Commenters also

stated that accident investigations have demonstrated the need for

improved records. Other commenters asserted that the proposed

requirement for bound books with sequential machine-numbered pages adds

an economic burden for the majority of compliant operators and another

way should be found, ``to foil the very few who are recalcitrant.''

Other commenters stated that since all records currently include dates

and times, machine-numbered pages are unnecessary.

Some record books that are currently in use and acceptable under

the existing standards are vulnerable to misuse or manipulation. For

example, under the existing rule, records could be kept in a spiral

notebook or even a loose leaf binder. The final rule addresses this

issue by requiring that records be made in books that are secure and

not susceptible to alteration. Examples of books that are considered by

MSHA to be secure and not susceptible to alteration include, but are

not limited to, record books that are currently approved by state mine

safety agencies, and permanently bound books. Examples of books that

would not be considered books that are secure and not susceptible to

alteration include loose leaf binders and spiral note books.

Several commenters advocated the use of computers for the storage

and retrieval of records. In support of this approach, the commenters

cited computer records as being highly accurate, requiring less storage

space and facilitating data retrieval. Other commenters expressed

concern for the security of records stored electronically, and offered

examples of breaches of security in record systems at banks and

national security installations as evidence to support this concern.

Electronic storage of information and assessing it through

computers is more and more a common business practice generally and in

the mining industry. Recognizing this trend, the final rule permits the

use of electronically stored records provided they are secure and not

susceptible to alteration, are able to capture the information and

signatures required, and are accessible to the representative of the

miners and the representatives of the Secretary. Based on the

rulemaking record, MSHA believes that electronic records meeting these

criteria are practical and as reliable as traditional records.

In the preamble to the proposal, MSHA expressed its intent to

require a hard copy printout of the information stored electronically

to be available within 1 hour of a request, and to require backing up

of the information within 24 hours. Commenters objected to making the

records available within 1 hour as being too stringent and

unnecessarily requiring a person to be on duty at all times. MSHA

agrees that the requirement would be overly burdensome and has not

included it in the final rule. Similarly, MSHA has not included a

specific requirement for backing up the computer data. The final rule

requires that the records be secure. This encompasses backing up the

data as appropriate to the conditions and electronic storage system

used at the mine. Upon reconsideration, MSHA has concluded that an

additional specific requirement would be an unnecessary burden and has

not included it in the rule.

A variety of comments were received regarding the countersigning of

certain records by the mine foreman, and the time frame permitted for

countersigning. The final rule adopts the proposal that the mine

foreman must countersign the record by the end of the mine foreman's

next regularly scheduled working shift. The mine foreman is the person

most responsible for the day-to-day operation of the mine. It is

essential for the health and safety of the miners that the mine foreman

be fully aware of the information contained in examination reports so

as to be able to allocate resources to correct safety problems as they

develop. Allowing until the end of the mine foreman's next regularly

scheduled working shift to countersign the reports assures that the

mine foreman is aware of the results of the examination in sufficient

time to initiate corrective actions. In response to commenters, the

final rule allows a mine official equivalent to a mine foreman to

countersign the records.

Some commenters suggested that the time for countersigning is

unnecessarily long, and that the final rule should restore a previous

requirement that countersigning be completed ``promptly.'' The term

``promptly'' involves a level of ambiguity that is eliminated by

specifying the time for countersigning records. The record does not

show that the time set by the final rule would expose miners to safety

or health risks. Also, hazardous conditions are required to be

corrected immediately.

Commenters suggested that the term ``mine foreman'' be replaced by

a ``certified person responsible for ventilation of the mine or his

designee.'' Another commenter suggested that the record could be

countersigned by the mine foreman or any other mine official

responsible for the day-to-day operation of the mine. Commenters stated

that some operations no longer use the terms ``mine foreman'', ``mine

manager,'' or ``superintendent.'' To provide for alternative management

titles, the final rule incorporates the phrase ``or equivalent mine

official.''

Numerous comments were received regarding the requirement of the

proposal for second level countersigning by the mine superintendent,

mine manager, or other mine official to whom the mine foreman is

directly accountable within 2 scheduled

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production days thereafter. Commenters objecting to the proposal stated

that higher level management should be able to delegate responsibility,

noting that often this level of official has more than one mine to

oversee and may not necessarily be available within the proposed two

days. One commenter suggested allowing three days for second level

countersigning in order to recognize that such an official often has

numerous obligations and to allow for normal absences. Other commenters

simply recommended that the second level countersigning be deleted.

Another commenter stated that some states hold the mine foreman

legally responsible, that the mine foreman should correct hazardous

conditions immediately and withdraw miners as appropriate, and that the

second level countersigning would add no measure of safety. One

commenter noted that in many cases the mine manager or superintendent

is not a certified individual and long periods may elapse during which

this person does not go underground. In these instances, the person

countersigning would have little or no understanding or first hand

knowledge of the conditions in the mine. Commenters stated that

countersigning by the mine foreman is adequate notification to the

operator of any deficiency and that the mine foreman has the necessary

resources and responsibility to correct any situation noted in the

records.

Other commenters supported the proposal noting that second level

countersigning would provide an additional level of accountability.

These commenters also suggested that in the event of a major accident,

the second level countersigning requirement would be important in fully

assessing the contributing causes.

MSHA has determined that countersigning by the mine foreman or

equivalent mine official, as specified in the final rule, provides the

means necessary to detect and correct developing hazards in a mine.

Countersigning by the mine foreman assures the necessary notification

to an official with the knowledge of the day-to-day operation of the

mine having the authority to maintain the mine in a safe operating

condition. Agency experience has demonstrated that higher level mine

officials commonly lack hands-on involvement or in-depth knowledge of

the specific conditions underground or how the highly detailed

ventilation rules impact upon those conditions. Therefore,

countersigning by a mine official at a higher level does not assure any

additional level of safety and imposes an unnecessary burden.

B. Section-by-Section Discussion

The following section-by-section portion of the preamble discusses

each provision affected. The text of the final rule is included at the

end of the document.

Section 75.301 Definitions

The final rule revises the definition of return air to permit

operators to designate certain air courses as return air courses for

the purpose of ventilating structures, areas or installations that are

required to be ventilated to return air courses and for ventilating

seals when the air in the air course will not be used to ventilate

working places. Thus, an operator wishing to split air off of an intake

for the purpose of ventilating shops, electrical installations, or for

other purposes, could designate the air course into which the split is

directed as a return provided the air in the air course would not be

used to ventilate working places or other locations, structures,

installations or areas required to be ventilated with intake air.

Commenters generally agreed with the change. However, one commenter

expressed the concern that air currents ventilating electrical

installations could be coursed to the conveyor belt entry before being

coursed to a redesignated return air course, and thus not vented

directly to a return. The commenter expressed the opinion that because

the air is not vented directly to a return under this scenario, the

rule would not permit this practice. MSHA does not agree with the

commenter's interpretation and the final rule, consistent with

Sec. 75.340, permits this practice.

MSHA does not anticipate that operators will need to redesignate

air courses on a routine basis. When questions arise as to the need to

redesignate an intake as a return, the operator should contact the

local MSHA office. In order that all interested persons are made aware

when an air course is redesignated, the final rule requires in

Sec. 75.372, Mine ventilation map, that such redesignated air courses

be shown on the mine's ventilation map.

Section 75.310 Installation of Main Mine Fans

The main mine fans serve a vital role in providing ventilation to

prevent methane accumulations and possible explosions as well as

providing miners with a healthful working environment. Section 75.310

is primarily directed at protecting the main mine fans from fires and

damage in the event of an underground explosion so that necessary

ventilation can be maintained. Monitoring of the fans to assure that

they are operating properly is an element of this protection. The final

rule for Sec. 75.310 revises paragraphs (a) and (c) of the existing

rule. The revisions address: (1) automatic signals for fan stoppage,

(2) pressure recording devices, and (3) main mine fan monitoring

systems.

Paragraph (a)(3) of Sec. 75.310, like the proposal, requires each

main mine fan to be equipped with an automatic device that gives a

signal at the mine when the fan either slows or stops. The existing

rule does not specify where the signal is to be given. Commenters

supported the proposal stating that a signal alarming at a location

away from the mine site would rely on overland communication lines to

transmit the signal, with the person receiving the signal then

notifying the mine. These overland communication lines are subject to

weather and other potential sources of damage, which could result in a

disruption of the communication. Other commenters objected to the

proposal, however, stating that the ability of a mine operator to

consolidate monitoring of several mines at one single location is a

very efficient and cost-effective practice and should not be

arbitrarily prohibited. Further, they stated that there would be

absolutely no delay in contacting the miners from this central location

should a fan malfunction occur. For clarity and for increased safety,

the final rule requires that the signal be given at the mine. MSHA

believes that in the case of a fan stoppage, this will assure more

timely notice to miners, and hence, a more effective safety response.

The requirement that the signal be given at a surface location at the

mine does not preclude the signal from also being given elsewhere, such

as at a central office, as long as it is given at the mine.

Paragraph (a)(3) of Sec. 75.310 requires that a responsible person,

designated by the operator, shall always be at a surface location at

the mine where the signal can be seen or heard while anyone is

underground. In addition, the responsible person must be provided with

two-way communication with working sections and with other established

locations where persons are normally assigned to work. Commenters

supported the proposal stating that the changes provide clarification

and specificity. Other commenters agreed with the proposed concept of

two-way communication but felt that the wording, ``established

locations where persons are normally assigned to work'' is ambiguous

and subject to misinterpretation. Some commenters

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objected to the proposed requirement stating that (1) it is redundant

of Sec. 75.1600 Communications; (2) properly the subject of a separate

rulemaking under Sec. 75.1600 or; (3) it is vague, ambiguous, or

subjective. Section 75.1600 only requires two-way communication between

the surface and working sections and does not identify that this

communication must be provided to a location where a person can see or

hear the fan alarm signal. Commenters suggested that the requirement be

revised to more specifically quantify locations where persons are

normally assigned to work. MSHA recognizes that, as proposed, the

standard might result in misinterpretation and the final rule has been

reworded to read, ``* * * two-way communication with working sections

and work stations where person(s) are routinely assigned to work for

the majority of a shift.''

Some, but not all, outby areas where two-way communication would be

required by the final rule include; shops, attended belt transfer

points, attended rail car loading points, and attended underground coal

storage bins and hoppers. It is not intended that this communications

capability be provided in areas where secondary roof support is being

installed or where rock dust is being applied, or at unattended

underground pumps, or in areas such as return air courses, bleeder

entries and conveyor belt haulageways other than at belt transfer

points. The requirement that two-way communication be provided to work

stations where persons are routinely assigned to work for the majority

of a shift is intended to help assure that these persons receive prompt

notification of fan stoppages. Because these work stations are off the

working section, a lack of communication capabilities could result in

delays in notification and therefore delays in egress from the mine.

Paragraph (a)(4) of the existing rule requires that main mine fans

be equipped with a pressure recording device or with a main mine fan

monitoring system but exempts from this requirement mines permitted to

shut down main mine fans under Sec. 75.311.

The final rule eliminates this exemption and requires that all main

mine fans be equipped with a pressure recording device or a main mine

fan monitoring device. For mines not currently required to have such a

device, MSHA has provided for a 1 year phase in period to allow mine

operators time to effectively plan and implement the necessary changes.

One commenter suggested that all main mine fans at all mines be

required to operate continually and further suggested that all main

mine fans be equipped with pressure recording devices and main mine fan

monitoring systems. In support of this suggestion, the commenter stated

that continuous fan pressure recording devices would have a positive

impact on safety at these operations. Such devices will provide

necessary information to operators and miners at operations affected by

this change. MSHA has not included one commenter's suggestion that main

mine fan monitoring systems be required for all main mine fans. While

MSHA supports and encourages the use of this advanced technology the

Agency does not believe that it is appropriate to mandate it for all

mines because daily fan examinations coupled with pressure recording

devices have proved to be adequate over the years. Also, MSHA does not

adopt a suggestion that main mine fans at all mines be required to

operate continuously.

Paragraph (a)(4) of the final rule requires that when a pressure

monitoring device is used in lieu of a pressure recording device, it

must produce a continuous graph or chart of the fan pressure. A hard

copy of the continuous graph or chart must be printed at regular

intervals of not more than 7 days. This provision permits the use of

relatively recent advances in technology for monitoring main mine fan

pressure provided a continuous record of the fan pressure is provided.

In the proposal, MSHA specifically solicited comments as to an

appropriate polling frequency that would provide a record that is

substantially continuous. In response to this request, one commenter

proposed that a polling frequency of two seconds is necessary to take

full advantage of available technology. This commenter stated that

continuously means constant or unbroken and that a continuous record

should require a polling frequency of not greater than 2 seconds.

Another commenter, an instrument manufacturer, suggested that a one

minute sampling interval is definitely feasible. Main mine fan

monitoring, when used, is often part of a more comprehensive mine-wide

atmospheric monitoring system (AMS), and to require that the fan be

polled every two seconds could delay the polling of other important

sensors. Additionally, because these pressure monitoring devices are

intended to be used in lieu of the traditional circular pressure

recorder they must provide a substantially equivalent record.

Experience by MSHA engineers following mine explosions and during more

routine ventilation survey work has shown that the accuracy to which a

7-day, circular recording chart of the type normally used can be read

is on the order of several minutes. MSHA would expect that the polling

frequency for a pressure recording device used in lieu of a pressure

recorder would be no more than one (1) minute.

MSHA received a number of comments in response to the proposed

requirement in paragraph (a)(4) that when a pressure recording device

other than a circular pressure recorder is used, a hard copy of the

continuous graph or chart be generated at not more than 7-day

intervals. Comments ranged from requiring daily printouts to not

requiring any printout except when requested by an Authorized

Representative of the Secretary. In response to these comments, the

final rule retains the requirement for a hard copy of the continuous

graph or chart be generated at not more than 7-day intervals. In light

of MSHA's stated position to permit records of examinations to be

stored electronically, the final rule permits the record of main mine

fan pressure to be stored electronically provided the record is secure

and not susceptible to alteration.

Paragraph (c) of Sec. 75.310 specifies requirements for main mine

fan monitoring systems if used under Sec. 75.312. Commenters suggested

that the requirements were repetitive, confusing, and would discourage

mine operators from using monitoring systems which could provide more

protection. MSHA believes that the requirements in paragraph (c) are

necessary to effectively monitor a fan, particularly when these systems

are used in lieu of daily fan examinations.

Paragraph (c)(3) of Sec. 75.310 of the proposal would have required

that main mine fan monitoring systems provide, on demand, a printout of

the monitored parameters, including the mine ventilating pressure.

Several commenters objected to the requirement that a printout be

provided ``on demand.'' As interpreted by these commenters, this

standard would require that the operator provide a printout at any time

it is requested. As explained in the preamble to the proposal, ``* * *

the monitoring system would be required to have the capability of

providing (emphasis added), on demand, a printout of the information

being monitored. This capability is intended to facilitate the review

of the information by mine management required in Sec. 75.312(b).'' The

commenters misinterpreted the purpose for the standard. MSHA

recognizes,

[[Page 9769]]

however, the merits of being able to obtain a printout within a

reasonable period of time. Therefore, the final rule requires that a

main mine fan monitoring system used to satisfy the requirements of

Sec. 75.312 provide a printout of the monitored parameters, including

the mine ventilating pressure, within a reasonable period, not to

exceed the end of the next scheduled shift during which miners are

underground.

Paragraph (c)(5) of Sec. 75.310 requires that two-way communication

be provided between a surface location at the mine where the signals

from the fan monitoring system can be seen or heard and working

sections and other established locations where persons are normally

assigned to work for the majority of the shift. Except for minor

editorial changes, this requirement is the same as the proposal.

Comments on this proposal were the same as comments on proposed

paragraph (a)(3). Several commenters supported the proposal stating

that the changes provide clarification and specificity. Other

commenters agreed with the proposed concept of two-way communication

but felt that the wording, ``established locations where persons are

normally assigned to work'' is ambiguous and subject to

misinterpretation. Some commenters objected to the proposed requirement

stating that (1) it is redundant of Sec. 75.1600 Communications; (2)

properly the subject of a separate rulemaking under Sec. 75.1600 or;

(3) it is vague, ambiguous, or subjective. Section 75.1600 only

requires two-way communication between the surface and working sections

and does not identify that this communication must be provided to a

location where a person can see or hear the fan alarm signal.

Commenters suggested that the requirement be revised to more

specifically quantify locations where persons are normally assigned to

work. MSHA recognizes that, as proposed, the standard might result in

misinterpretation and the final rule has reworded the proposal to read,

``* * * two-way communication with working sections and work stations

where person(s) are routinely assigned to work for the majority of a

shift.''

Some, but not all, outby areas where two-way communication would be

required by the final rule include; shops, attended belt transfer

points, attended rail car loading points, and attended underground coal

storage bins and hoppers. It is not intended that this communications

capability be provided in areas where secondary roof support is being

installed or where rock dust is being applied, or at unattended

underground pumps, or in areas such as return air courses, bleeder

entries and conveyor belt haulageways other than at belt transfer

points. The requirement that two-way communication be provided to work

stations where persons are routinely assigned to work for the majority

of a shift is intended to help assure that these persons receive prompt

notification of fan stoppages or other problems with the fan that might

require withdrawal of miners. Because these work stations are off the

working section, a lack of communication capabilities could result in

delays in notification and therefore delays in egress from the mine.

Section 75.311 Main Mine Fan Operation

The main mine fan provides the pressure that causes air to move

through the mine to dilute and carry away explosive and toxic gases,

dusts and fumes. As such it is the most important part of the

ventilation system. Section 75.311 requires fans to be continuously

operated to provide constant ventilation to underground areas and

specifies precautions for planned fan stoppages. It also addresses the

repair of main mine fans, monitoring of fan signal devices on the

surface, and protection against fires around fans and intake air

openings.

The final rule revises paragraph (d) of Sec. 75.311, which

addresses the notification of mine officials of any unusual variance in

mine ventilation pressure and requires the prompt repair of electrical

or mechanical deficiencies. The final rule requires immediate

notification and the prompt institution of corrective action or

repairs.

Commenters suggested deletion of the word ``unusual'' maintaining

that this term makes the requirement vague and subject to different

interpretations. These commenters suggested substituting the phrase,

``that could materially affect the safety and health of persons in the

mine'' to describe the type of pressure variance that would require

action. In making this recommendation, the commenters cited similar

language in existing Sec. 75.324(a)(1) that, according to the

commenters, is understood throughout the coal mining community. Section

75.324(a)(1) concerns alterations of the main ventilation air current

or any split of the main air current. The final rule does not adopt

this recommendation. Minor fluctuations in fan operating pressure are

normal; however, unusual changes can be indications of changes in fan

operation or changes underground, such as roof falls or loss of

ventilation controls, that require prompt attention and corrective

action. In addition, MSHA has 25 years of experience with the phrase

``unusual variances in mine ventilation pressure'' and is unaware of

significant difficulties with this terminology.

Commenters questioned what constitutes an ``electrical or

mechanical deficiency'' for the purposes of Sec. 75.311. The purpose of

the standard is to assure that a problem with main mine fans is

corrected promptly and that the proper persons are notified that the

problem exists. The types of electrical or mechanical deficiencies

requiring action under paragraph (d) are those that can interfere with

mine ventilation. In addition, MSHA has 25 years of experience with the

phrase ``electrical and mechanical deficiencies'' and is, again,

unaware of any significant difficulties with the use of this

terminology during this time frame.

Commenters also addressed the proposal that the ``mine

superintendent, assistant mine superintendent, or mine foreman'' be

notified immediately when an unusual variance in mine ventilation

pressure is observed, or when an electrical or mechanical deficiency in

a main mine fan is detected. The final rule does not retain the mine

superintendent or the assistant mine superintendent as mine officials

to be notified. Commenters stated that this provision provides a

measure of safety to the miners by requiring that specific mine

managers be notified of possible main mine fan problems, while the

existing standard specifies that such a situation must be investigated.

Other commenters, however, suggested that the persons identified for

notification under the proposal may not be the most qualified to handle

the problem. They also indicated that the notification requirement

could unnecessarily delay appropriate action by other responsible

persons. The commenters further stated that the mine superintendent or

assistant mine superintendent may not be at the mine and that a

certified person would be in charge who should be permitted to take the

appropriate action. The proposed requirement that certain mine managers

be notified immediately was not intended to require that these

individuals personally take the necessary actions to respond to the

problem with the main mine fan. Neither was it intended that they be

notified of such a problem, to the exclusion of all others. The

objective of the rule is to assure that the appropriate actions are

taken as soon as possible. Additionally, notification of specified mine

officials is intended to assure that those persons who are responsible

for the mine are aware of the problem. The

[[Page 9770]]

final rule, therefore, retains the requirement that certain mine

managers be notified of any unusual variance in the mine ventilation

pressure or if an electrical or mechanical deficiency of a main mine

fan is detected.

The final rule does, however, delete reference to notification of

the mine superintendent or assistant mine superintendent. As discussed

in relation to the countersigning of records, the mine superintendent

is quite often not a certified person and is only periodically present

at the mine. In addition, consistent with other sections of the final

rule and recognizing that the term mine foreman is not used at some

mines, the final rule requires that if an unusual variance in the mine

ventilation pressure is observed, or if an electrical or mechanical

deficiency of a main mine fan is detected, the mine foreman or

equivalent mine official, or in the absence of the mine foreman or

equivalent mine official, a designated certified person acting for the

mine foreman or equivalent mine official shall be notified immediately.

As with the proposal, the final rule requires that appropriate action

or repairs shall be instituted promptly. It is not intended that the

appropriate action or repairs be delayed until the mine foreman or

equivalent mine official is notified.

During a series of informational meetings held by MSHA following

publication of the existing rule, questions arose concerning the

operation of back-up fans. For informational purposes, the preamble to

the proposal included a detailed discussion of questions about the

operation of back-up fans under the ventilation regulations and

solicited comments. MSHA did not propose any rule changes, nor does the

final rule contain specific provisions for back-up fans. When a back-up

fan operates in place of the main mine fan, the back-up fan is

considered to be a main mine fan and all subpart D requirements for

main mine fans are applicable.

Section 75.312 Main Mine Fan Examinations and Records

Proper operation of main mine fans is critical to mine ventilation

and the prevention of methane accumulations and possibly methane

explosions. Recognizing the importance of the main mine fan,

Sec. 75.312 requires that each main mine fan be examined at least once

each day that the fan operates unless the fan is continuously monitored

with a main mine fan monitoring system. Through daily examinations or

continuous monitoring of critical parameters, the operator can

determine if problems with the fan are developing and correct these

problems before ventilation is affected.

The final rule removes existing paragraph (g)(2), revises existing

paragraphs (a), (b)(1), (c), (d), (g)(1) and (h), redesignates existing

paragraph (f) as (f)(1), and adds new paragraphs (f)(2) and (g)(2).

Paragraph (a) of the final rule, like the existing rule, requires daily

examination of main mine fans unless a fan monitoring system is used.

In addition, paragraph (a) specifies that an examination of the main

mine fan is not required on days when no person goes underground. An

examination of the fan, however, is required prior to anyone entering

the mine. The purpose of this examination, as stated in paragraph (a),

is to assure the electrical and mechanical reliability of the fan.

When a fan monitoring system is used, the final rule requires a

daily review of the data from the monitoring system to be made, except

on days when no person goes underground. A review of the data from the

monitoring system must be completed, however, prior to anyone entering

the mine.

Fan examinations or review of fan monitoring system data are

required to be performed by a trained person designated by the

operator.

Commenters questioned the use of the term ``assure'' in paragraph

(a) when referring to the electrical and mechanical reliability of main

mine fans. MSHA uses the term ``assure'' in this context as defined in

Webster's Third New International Dictionary, Unabridged, 1993 edition,

to mean, ``to make safe, to give confidence to.'' The sense of this

definition is consistent with the intended purpose of the examination.

The term does not mean to ``guarantee'' safety, as suggested by one

commenter.

Commenters suggested that the final rule require the examination of

main mine fans for proper operation be conducted by an individual

trained as part of the mine operator's training plan required by MSHA's

comprehensive training regulation in part 48 of 30 CFR. Other

commenters understood the proposal to require training of fan examiners

under part 48, and objected to such a requirement. These commenters

suggested that the person conducting the fan examination be one who has

received training through experience or has been trained by an

experienced person, or by the fan manufacturer. The final rule does not

require fan examiners to be trained as part of the operator's part 48

training plan. Instead, the final rule specifies that fan examiners

must be trained sufficiently to have the skill and knowledge to

ascertain whether the fan is in proper working order, mechanically and

electrically.

Paragraph (a) requires a daily physical examination of the main

mine fan, unless a fan monitoring system is used. If a fan monitoring

system is used, paragraph (b) requires a weekly physical examination of

the main mine fan, a weekly test of the monitoring system, and a daily

review of the main mine fan monitoring data. Commenters suggested that

even if a main mine fan is equipped with a monitoring system, the fan

should still be subject to daily physical examinations because a fan

monitoring system is not capable of disclosing all conditions that a

physical inspection could disclose. The final rule does not adopt this

suggestion. A weekly physical examination of the fan and a test of the

monitoring system coupled with a daily review of the monitoring data

provides reasonable assurance that a mine fan is operating reliably.

Commenters suggested that the proposed requirement of paragraph (b)(1)

requiring a daily review of main mine fan monitoring system data is

unnecessary and redundant. These commenters suggested that the system

need only be capable of producing a printout because the systems would

automatically alarm anytime an electrical or mechanical deficiency

exists. Requiring a daily review of the monitoring system data,

according to these commenters, could discourage the use of improved

technology. Other commenters noted that operators currently using fan

monitoring systems conduct a daily review of the data at the present

time and that the requirements to review the data would provide an

additional measure of safety for the miners. MSHA believes that a daily

review of data from fan monitoring systems is needed to assure that

mine management is made aware of any operational changes or trends in

monitored parameters. Main mine fans provide the source for mine

ventilation and, therefore, are critical to miners' safety. As

discussed earlier, these daily reviews of data are designed to

complement the physical examinations of the fan.

The final rule adopts the requirements of proposed paragraphs

(b)(1)(ii) (A) and (B) and requires that when a fan monitoring system

is used as provided under paragraph (a), a trained person designated by

the operator must test the system for proper operation at least every 7

days. Commenters objected that it is redundant because a fan monitoring

system is capable of monitoring itself and can automatically provide a

warning when a fan malfunction occurs. These commenters also stated

that if the

[[Page 9771]]

system is continuously operated, the system is self-tested for proper

operation several times a minute and that the 7-day test is

unnecessary. The commenters suggested that the 7-day test only be

conducted if the fan monitoring system is not continuously operated.

For continuously operating fans an examination of the fan should more

appropriately be conducted monthly, according to these commenters.

Requiring more frequent checks the commenters maintain would discourage

the use of fan monitoring systems.

The final rule does not adopt these suggestions. While MSHA

encourages the use of fan monitoring systems, excessive reliance on the

self-monitoring features of these systems is incompatible with the

importance of reliable operation of main mine fans. MSHA does not

anticipate that the final rules for examination requirements will

discourage the use of fan monitoring systems. Main mine fans without a

monitoring system are required to be examined daily, while fans with

monitoring systems are required to be examined every seven days.

Paragraphs (c) and (d) of Sec. 75.312 of the final rule continue in

effect the requirements that tests of the automatic fan signal device

and automatic closing doors, when these doors are required, be

conducted at intervals not to exceed 31 days. The specified means of

testing these devices and doors is by stopping the fan. The proposal

would have permitted an alternative test not involving stopping the fan

if the alternative method provided the same level of assurance that the

signal device or door would function as intended during fan stoppages.

Two commenters favored the proposal and suggested that there is no need

to approve alternate means of testing fan signal devices in the mine

ventilation plan. These commenters expressed the opinion that each

authorized representative should be capable of ascertaining the

validity of the alternative method. The commenters did not make a

similar suggestion relative to the alternative means provision proposed

in paragraph (d) for automatic closing doors. Another commenter opposed

the use of alternative tests stating that it would be premature to

adopt a provision for an alternative test to stopping the fan when such

a test has not as yet been developed. MSHA has reconsidered the

proposal and the final rule continues to require that the tests of fan

signal devices and automatic closing doors be conducted by stopping the

fan. Should an operator develop an alternative method that provides the

same level of protection as stopping the fan, the petition for

modification process is available for an operator to obtain approval.

Paragraphs (c) and (d) permit underground power to remain energized

during fan signal and automatic closing door testing, notwithstanding

the requirements of Sec. 75.311. If the fan is not restarted within 15

minutes, the final rule requires that underground power be deenergized

and no one is permitted to enter any underground portion of the mine

until the fan is restarted and an examination is conducted.

Additionally, paragraphs (c) and (d) require that only persons

necessary to evaluate the effect of the fan stoppage or restart, or to

perform maintenance or repair work that cannot otherwise be done while

the fan is operating, are permitted underground.

Some commenters objected to limiting the persons who can be

underground during fan signal and closing door tests. Other commenters

objected to anyone being permitted underground during the stoppage of a

fan to conduct the required tests. These commenters expressed the

opinion that all necessary work can be performed with the fan operating

and therefore, when a fan is shut down to test the fan signal device or

the automatic closing doors no one should be underground.

Some work, such as working immediately inby a blowing fan, could

place workers at risk by exposing them to extreme temperatures, effects

of the high velocity air stream, or excessive noise levels when the fan

is operating. In addition, repair work within a shaft can more safely

be done when a fan is stopped. The rule, therefore, retains the

exception that permits persons underground during intentional fan

stoppages to evaluate the effect of the fan stoppage or restart, or to

perform maintenance or repair work that cannot otherwise be done while

the fan is operating.

Paragraphs (c) and (d) of the final rule are reworded to clarify

that during the required tests, power circuits may remain energized

only if no person is underground. Therefore, if an operator elects to

evaluate the effect of the fan stoppage or restart, or to perform

maintenance or repair work that cannot otherwise be done while the fan

is operating, simultaneous with the tests required, power circuits must

be deenergized in accordance with Sec. 75.311(b)(3). Additionally, in

accordance with Sec. 75.311(b)(2), all mechanized equipment must be

shut off.

Paragraph (f)(1) of the final rule retains the longstanding

requirement that the person performing main mine fan examinations

certify by initials and date at the fan or another location specified

by the operator that the examinations were made. Each certification is

required to identify the main mine fan that was examined. When daily

fan examinations are conducted, daily certification is required. When a

main mine fan monitoring system is used and fan examinations are

conducted at 7 day intervals, certification is required each time the

fan is examined.

One commenter offered suggested wording that would eliminate the

option of certifying that the examination was completed at a location

other than the fan being examined. This suggestion has not been adopted

and the final rule retains the flexibility for certifications to be

made away from the fan.

Paragraph (f)(2) of the final rule requires that when a main mine

fan monitoring system is used, a daily printout of the system's data

must be certified to indicate that the daily review was completed.

While some commenters generally agreed with this requirement other

commenters suggested that an alternative should be provided for systems

which are continuously operated and supervised. In such cases, the

commenters suggested that immediate notification of the mine foreman

when a deficiency arises would be appropriate, together with

maintaining the internal records of data gathered by the systems for

one year.

The suggested alternative is not included in the final rule. MSHA

believes that documentation that monitoring system data is being

reviewed is necessary to provide reasonable assurance that mine

management is aware, on a timely basis, of the operating condition of

the fan being monitored. However, to reduce the burden of this

requirement, the final rule in paragraph (f)(2) does permit the

electronic certification of the review of the data generated by a fan

monitoring system. As with electronically kept records, the rule would

require that the electronic certification include handwritten initials

and dates. A discussion of comments concerning the use of computers to

maintain records can be found in the General Discussion of this

preamble.

Paragraph (g)(1) of Sec. 75.312 requires that by the end of the

shift on which the examination is made, persons making main mine fan

examinations must record all uncorrected defects found during the

examination that may affect the operation of the fan. The rule also

specifies that records be maintained in a book that is secure and not

susceptible

[[Page 9772]]

to alteration, or electronically in such a manner as to be secure and

not susceptible to alteration. The proposal would have required all

defects found during the main mine fan examination that may affect the

operation of the fan to be recorded whether corrected or uncorrected.

Some commenters objected to recording defects that ``may'' affect

the operation of the main mine fan, and suggested only defects that do

affect the operation of the main mine fan and that are not corrected by

the end of the shift, need to be recorded.

Some commenters asserted that a record of ``all'' defects should be

required in order to identify recurring problems that may lead to

bigger problems. These commenters interpreted the proposal to require

such a record. The final rule is intended to address problems found

during fan examinations that may indicate more serious defects and

ultimately lead to a fan failure and that cannot be corrected by the

end of the shift. The objective is to record defects of a nature and

seriousness that could result in a fan failure, but not to record

defects that are so minor that it would be unreasonable to expect fan

failure to result. Another commenter stated that recording all defects

that may affect fan operation would result in excessive paperwork of

little value. This commenter also suggested that if mine ventilation

does become ineffective, the workers are to be withdrawn from the mine.

MSHA is sensitive to concerns about recordkeeping. Therefore, the final

rule requires that all uncorrected defects which are found during the

examination that may affect fan operation be recorded. In this manner,

miners on the oncoming shift are aware of problems with the fan that

potentially could impact underground ventilation.

Commenters supported the use of electronic media as a substitute

for specific types of record books. Commenters pointed out that almost

all such systems incorporate recordkeeping functions and that

significant variances from the norm are easily noted. They concluded

that the computer monitoring systems provide superior protection for

the miners. The final rule permits, in paragraph (g)(1), the use of

electronically stored records for main mine fan examinations provided

the records are secure, are able to capture the information and

signatures required, and are accessible to the representative of the

miners and the representatives of the Secretary.

As with other records required by this rule, paragraphs (g)(2) and

(g)(3) require that records required by Sec. 75.312 must be made in

books that are secure and not susceptible to alteration, or

electronically in such a manner as to be secure and not susceptible to

alteration. A detailed discussion of record books and the use of

computers to maintain records can be found in the General Discussion of

this preamble.

Paragraph (g)(2) of the existing rule requires that at mines

permitted to shut down main mine fans under Sec. 75.311, if a pressure

recording device is not used, a record shall be made, in a book

maintained for that purpose, of the time and fan pressure immediately

before the fan is stopped, and after the fan is restarted and the fan

pressure stabilizes. The final rule does not retain this requirement in

light of the new requirement of Sec. 75.310(a)(4) that all main mine

fans be provided with a pressure recording device or an option of the

use of a fan monitoring system. This new requirement eliminates the

need for an additional record of the time and fan pressure made

immediately before the fan is stopped and after the fan is restarted

and the fan pressure stabilizes. This information is obtained from the

pressure recording chart, which records the pressure continuously and

automatically, thus maintaining the protection afforded the miners.

Paragraph (h) of the final rule requires that the records required

by Sec. 75.312 be maintained at a surface location at the mine for one

year and be made available for inspection by authorized representatives

of the Secretary and the representative of miners. Comments were

generally favorable on this proposal. A discussion of comments

concerning the use of computers to maintain records can be found in the

General Discussion of this preamble.

As with the other provisions of the final rule allowing electronic

certification or recordkeeping, sufficient protections have been

included so that there is no reduction in protection from the existing

standards.

Section 75.313 Main Mine Fan Stoppage With Persons Underground

Section 75.313 was stayed by MSHA as explained in the introductory

section of this preamble. Generally, this standard is concerned with

protecting miners from the danger introduced when the main mine fan

stops, such as when there is a loss of power. Under these

circumstances, mine ventilation is interrupted, permitting gases such

as methane to accumulate. These conditions can lead to an explosion

ignited by electric circuits or the operation of equipment.

Paragraph (a)(3) of the final rule requires that if a main mine fan

stops, everyone shall be withdrawn from the working sections and from

areas where mechanized mining equipment is being installed or removed.

The language of the final rule is identical to the wording of stayed

Sec. 75.313 (a)(3). An in-depth discussion of provisions concerning the

installation and removal of mechanized mining equipment is presented in

the General Discussion section of this preamble.

The final rule revises paragraphs (c)(2), (c)(3), (d)(1)(i) and,

(d)(1)(ii) of the stayed standard. Paragraphs (c)(2) and (c)(3) require

that when a main mine fan stops with persons underground, the

underground electric power circuits shall be deenergized and mechanized

equipment shall be shut off. These rules further recognize an exception

to facilitate miners' evacuation from the mine. The exception

temporarily permits some circuits to remain energized and some

mechanized equipment to not be shut off, provided these circuits and

mechanized equipment are necessary to withdraw persons from the mine

and are located in areas where methane is not likely to migrate to or

accumulate. These circuits must be deenergized and the mechanized

equipment must be shut off as persons are withdrawn. The final rule

differs from the stayed standard by limiting the exception permitting

the use of these circuits or equipment to areas where methane is not

likely to migrate to or accumulate.

Paragraph (d)(1)(i) requires that when a fan stoppage lasts for

more than 15 minutes a preshift-type examination must be conducted

before persons other than designated examiners, are permitted to enter

any underground area of the mine. Examiners are permitted to re-enter

the underground area of the mine from which miners have been withdrawn

only after the fan has operated for at least 15 minutes unless a longer

period of time is specified in the mine ventilation plan. Paragraph

(d)(1)(ii) requires that when a fan stoppage lasts for more than 15

minutes, underground power circuits are not to be energized and

nonpermissible mechanized equipment is not to be started until a

preshift-type examination is conducted, except that designated

certified examiners may use nonpermissible transportation equipment in

intake airways to facilitate the conduct of the required examination.

Some commenters suggested that actions following fan stoppages are

best handled on a mine-by-mine basis through a plan approval process.

Along

[[Page 9773]]

these lines, commenters suggested that the fan stoppage plan approval

process previously used by MSHA should be used with only minor

modification to assure that plans do not become standardized, that is,

model the rule on a past standard with criteria for approval of fan

stoppage plans. Other commenters, while supporting the concept of fan

stoppage plans, proposed to tie the submission and approval of such

plans to total mine ventilation surveys and computer simulations

conducted by the operator every three months. According to one

commenter the data provided by these surveys would be used to determine

the adequacy of a fan stoppage plan.

The final rule does not adopt the suggestions of the commenters for

mine fan stoppage plans. One objective in this rulemaking is to reduce

the need for paperwork, such as plans, where reasonable, uniform

requirements can be developed. The final rule establishes the general

requirement that after a fan stoppage lasting more than 15 minutes,

mine power and equipment is to be shut down. However, experience shows

that using transportation equipment to facilitate mine evacuation is

often necessary, provided this is done where gas is not likely to

accumulate, and circuits are deenergized on the way out of the mine.

Some commenters suggested that the requirements in paragraphs

(c)(2) and (c)(3) limiting the use of transportation equipment to areas

and haulageways ``where methane is not likely to migrate to or

accumulate'' are inconsistent with certain state laws. As support for

this assertion, the commenters gave the example of the state of

Illinois' requirements for evacuating mines following an interruption

in ventilation, which does not expressly recognize limited use of power

and equipment to facilitate evacuation. State mine safety laws,

including Illinois', are similar to the final rule provisions for

evacuation after a mine fan stoppage. As a general rule, state mine

safety regulations that are more stringent than MSHA standards are not

considered to be in conflict with federal regulations, and the more

stringent safety requirement applies. In this case, if the Illinois

regulation would not permit temporary use of power and equipment to

facilitate evacuation, then the state law would not be inconsistent

with MSHA.

Several commenters objected to the wording, ``where methane is not

likely to migrate to or accumulate,'' in paragraphs (c)(2) and (c)(3),

as being vague. Other commenters stated that the rule's requirement was

simply good practice that would be heeded by prudent mine managers.

MSHA agrees that the terms and objectives of the final rule are

understood in the mining community, and believes that the determination

of whether methane may migrate from adjacent areas and enter travelways

and haulageways used by miners during withdrawal should be made on a

mine-by-mine basis. Therefore, the final rule retains the exception

that power circuits may remain energized and mechanized equipment may

be operated only if located in areas where methane is not likely to

migrate to or accumulate.

Some commenters stated that history does not support the need for

the requirements of paragraphs (c)(2) and (c)(3). Mine fan stoppages

unquestionably result in the existence of unventilated areas and may

result in highly hazardous methane accumulations. Although there have

been a limited number of ignitions/explosions directly attributable to

the operation of transportation equipment during a fan stoppage, the

true measure of the potential hazard addressed by this standard can be

seen in the ignitions and explosions that were the result of the

operation of transportation equipment in unventilated areas. Examples

of such types of accidents include: The 1972 Itmann No. 3 explosion, in

which 5 miners died; the 1976 Scotia Mine explosion, in which 15 miners

died; the 1982 Virginia Pocahontas No. 6 Mine explosion in which 1

miner was injured; the 1983 McClure No. 1 Mine explosion, in which 7

miners died; the 1983 Homer City Mine explosion in which a mine

examiner was killed; the 1983 Greenwich Collieries No. 1 Mine explosion

in which 3 miners were killed and 4 miners were injured and; the 1993

explosion at the Buck Mountain No. 2 Mine in which 3 miners were

injured. Given this history of explosions, it would not be prudent to

permit electric circuits to remain energized and mechanized equipment

to be operated in areas or haulageways where methane is likely to

migrate to or accumulate during a fan stoppage.

One commenter stated that the in-mine test necessary to determine

the likelihood of methane migration could only be done with the fan

stopped. The commenter questioned whether miners would be permitted

underground during the tests. To the extent the tests require the main

mine fan to be turned off, persons would be allowed underground to

evaluate the effect of the fan stoppage or restart.

Paragraphs (d)(1)(i) and (ii) address safety precautions for

reentering the mine after ventilation is restored. Key objectives of

these standards are the protection of the examiners and the safety of

miners returning to work.

As proposed, paragraph (d)(1)(i) would have required that when a

fan stoppage lasts for more than 15 minutes a preshift- type

examination be conducted covering the requirements of Sec. 75.360(b)

through (e) before persons, other than designated examiners, enter any

underground area of the mine. Commenters suggested that to provide the

level of protection desired, a complete preshift examination, including

the certification and recordkeeping requirements of Sec. 75.360(f)

through (g), should be required. Commenters pointed to the need for

miners reentering evacuated areas to be able to determine if the area

had been examined and urged that the final rule require the examiner to

certify by initial, date and time the areas examined.

MSHA agrees that clear notice to miners about which areas have been

examined is necessary and consistent with the objectives of the rule.

The final rule, therefore, adopts the proposal. A record of the

hazardous conditions found by examiners is required under Sec. 75.363

of the final rule. This record serves the purpose of providing mine

management with the information necessary relative to the existence and

correction of hazardous conditions in the mine. The final rule

incorporates these requirements by specifying that the scope of the

examination be conducted as described in Sec. 75.360(b) through (e).

Under paragraph (d)(1)(i) no one other than designated certified

examiners would re-enter any underground area of the mine until the

entire examination is completed. Commenters suggested that paragraph

(d)(1)(i) be revised to permit partial examinations following fan

stoppages and restarts under certain conditions. Under this suggested

approach, the examination would focus on the effectiveness of the

mine's ventilation system and methane accumulations in travelways, work

places or other areas where miners will work following the interruption

of ventilation. One commenter further suggested that an exception to

this examination be provided for noncoal producing shifts, where

persons are to work in the shaft, slope, drift, or on the immediate

shaft or slope bottom area. The commenter suggested the examination

following a fan stoppage could be limited to this area.

The final rule does not adopt this approach. Limiting the scope of

examinations following an interruption in mine ventilation to general

[[Page 9774]]

ventilation effectiveness and methane accumulation would not focus on

likely areas of concern. For example, no examination for hazards would

be required, and no air measurements to determine if the air is moving

in its proper direction and at its normal volume would be required. As

to the area of the mine required to be examined, only those places

where miners will return to work and the route of travel used to reach

these places must be examined. Thus, the final rule is sufficiently

flexible to meet the commenter's concerns about non- coal producing

shifts.

A question arose during public meetings as to the meaning of the

term on-coming shift in Sec. 75.360 when applied to Sec. 75.313. For

the purposes of Sec. 75.313(d)(1)(i) and (ii) the term ``persons on the

on-coming shift'' is interpreted as meaning persons on the shift on

which the fan is restarted. If a fan outage extends from one shift into

another, a preshift examination as required by Sec. 75.360 must be

completed before any person, except certified examiners designated to

conduct the examination, enters the mine.

Commenters also suggested that the final rule specify a minimum

time for the fan to run before examiners re-enter the mine so that

examiners are not unduly exposed to danger. Several commenters observed

that this is a general practice in the industry.

MSHA agrees that an important measure of safety is gained by

allowing the mine fan to run sufficiently long to begin reventilating

the mine before anyone enters. The final rule, therefore, provides

designated certified examiners shall enter the underground area of the

mine from which miners have been withdrawn only after the fan has

operated for at least 15 minutes unless a longer period of time is

specified in the approved mine ventilation plan. The 15 minute

provision will permit re- ventilation of entries in which examiners

will travel to take place and the examiners will then be traveling into

the mine in fresh air.

Proposed paragraph (d)(1)(ii) would have required that when a fan

stoppage lasts more than 15 minutes underground power circuits are not

to be energized and nonpermissible equipment is not to be started until

a preshift-type examination is completed. Commenters objected to the

proposal for various reasons. One commenter suggested that before power

is permitted to be energized a complete ventilation survey should be

required. Other commenters focused on the practical considerations

involved in conducting examinations and urged that use of

nonpermissible equipment for the transportation of examiners be

permitted.

As revised, paragraph (d)(1)(i) requires that the main fan when

restarted run for at least 15 minutes so that restoration of mine

ventilation is underway before anyone enters the mine. Once this is

accomplished, electrical circuits in shafts and slopes can be energized

safely as these areas are the first places to be reventilated by fresh

air. Accordingly, the final rule permits these circuits to be re-

energized after the mine fan has run for at least 15 minutes.

The final rule also permits examiners to use nonpermissible

equipment for transportation during the examination. The proposal would

have prohibited this practice. Some commenters supported the proposed

prohibition citing two mining accidents involving nonpermissible

equipment in unventilated areas. Other commenters objected to the

proposal not to allow the use of nonpermissible equipment to facilitate

examinations following the restart of a main mine fan. These commenters

stated that travelways and equipment roadways can be examined and

tested for the presence of methane, the results of the examination

called out, and typical nonpermissible transportation equipment placed

into operation to expedite the examination of the mine.

After considering all of the comments, MSHA has revised the

proposal and the final rule permits the use of nonpermissible

transportation equipment, in intake airways, to facilitate making the

examinations after an interruption in mine ventilation. Using

nonpermissible equipment in this fashion, in nonventilated areas, has

been a demonstrably safe practice for many years in the industry. In

addition, the requirement of running the fan for 15 minutes before

reentering the mine, together with keeping the transportation equipment

in the intake airways where the main ventilating current travels first,

provides the desired level of safety.

Under proposed paragraph (d)(2), if ventilation was restored to the

mine before miners reached the surface, all miners would have been

required to continue traveling to the surface. As proposed, designated

certified examiners would have been permitted to remain underground for

the purpose of beginning the required examination. The final rule does

not adopt the proposal and retains the language of the existing

standard.

While supporting the requirement that miners continue to the

surface after a fan is restarted, some commenters objected to

permitting certified persons to remain underground. These commenters

also took the position that once a fan has been off for more than 15

minutes, all efforts to restart the fan should be suspended, unless it

is known that it is safe to restart the fan. Other commenters expressed

significantly different views on both issues. A number of commenters

supported restarting the fan as soon as possible because the longer it

is off, the greater the potential hazard. MSHA concurs with this

reasoning and the final rule adopts this approach.

On the issue of requiring the evacuation to continue once it has

begun until the fan is restarted, even when ventilation is restored, a

number of commenters objected that such a requirement would result in

unnecessary delays and may result in additional safety risks. One

commenter stated that the proposal would not allow for the variables

that exist from mine to mine. Several commenters suggested that if the

operator has reason to believe that the time frame of the fan stoppage

would be less than the travel time or equivalent, the dangers of

traveling outby into possible pockets of dangerous gas buildup (or

other travel hazards) far outweigh the dangers of staying on the

section in intake air back from the face. This would also allow the

miners to remain on the section and proceed to the working places after

the fan has restarted and the working places have been examined by a

certified person.

MSHA disagrees with this position. In some mines, the time to

travel from the outside to the working sections can approach 1 hour.

Following the approach suggested, miners would remain on the section in

an unventilated mine for up to 1 hour. If at the end of this time

ventilation is still not restored, it is unclear whether the miners

then proceed to the surface, traveling through the same area the

commenter suggested might be hazardous some 45 minutes before.

The commenters stated further that, ``Forcing miners to walk out of

the mine could take hours and unnecessarily delay the restoration of

ventilation and resumption of operations.'' While there may be

instances where the time required to withdraw miners is increased, the

requirements in paragraphs (c)(2) and (c)(3) have no impact on the

restoration of ventilation. In fact, MSHA's position is that

ventilation should be restored as soon as possible following a fan

stoppage.

Lastly, a number of commenters suggested that when ventilation is

restored during evacuation, miners should be permitted to remain where

[[Page 9775]]

they are and return to working areas after an examination of inby areas

is completed. These commenters stated that no additional measure of

safety is gained by requiring miners to continue to the surface if

ventilation has been restored and the area in which the miners are

located is free of hazards. MSHA agrees and has retained the language

of the existing rule. By retaining the existing language, the general

practice of miners stopping their evacuation and waiting for examiners

to complete their work will continue. Under this approach, miners

remain in a safe location while ventilation of the mine is restored.

They do not return to any area of the mine until it has been determined

to be safe. The final rule does not prevent mine operators from having

miners continue to the surface if they so choose. Regardless of whether

miners remain where they are or continue to the surface, paragraph

(d)(1)(i) of the final rule requires that the fan operate for at least

15 minutes before the examination of the areas from which miners have

withdrawn is examined.

Section 75.320 Air Quality Detectors and Measurement Devices

Section 75.320 establishes the standards for the devices relied

upon to test for the presence of methane and other dangerous gases that

can accumulate in a mine. It generally requires that these devices be

approved and maintained in permissible and proper operating condition.

The final rule adds a new paragraph (e). It requires that

maintenance of instruments required by paragraphs (a) through (d) of

Sec. 75.320 to detect and measure air quality be done by a trained

person. The final rule does not include the proposal that before each

shift care shall be taken to assure the permissible condition of the

air quality detectors and other measurement devices to be used during

the shift. MSHA has concluded that this requirement would have been

redundant with paragraph (a) and is unnecessary. The final rule permits

an operator to send instruments to a repair facility or to the

manufacturer for regular servicing. Commenters at the informational

meetings and in later discussions on the existing rule stated that

maintenance by trained persons should be specified and that requiring

only that air quality detectors and other measurement devices be

maintained in permissible condition would not be sufficient. They

stated that without a requirement for maintenance to be done by a

trained person, similar to that which existed in the previous standard,

a person with less than the necessary understanding of the instrument

and the permissibility requirements might be assigned the task.

Several commenters suggested that the requirements of paragraph (e)

are redundant with general requirements found elsewhere in the

standards and are unnecessary. Other commenters felt that the current

performance standard is adequate, but that the meaning of ``assure'' is

unclear. Still other commenters indicated that the assurance of

permissibility is properly the responsibility of the user. One

commenter noted that the instruments are intrinsically safe and that

the manufacturer's instructions are sufficient. MSHA agrees that the

general requirement under paragraph (a), together with requiring

trained persons, is adequate.

Another commenter suggested that a formal written maintenance

program be required. Under this suggestion, the program would be

subject to MSHA approval and would include records of all maintenance

and calibrations to be made by the end of the shift. This commenter

also suggested that existing paragraph (a) be revised to provide for

more frequent calibration by inserting the phrase ``* * * or more often

if necessary * * *.'' This suggestion has not been adopted since

compliance with the proper operating and permissibility provisions of

paragraph (a) would result in more frequent calibration, if necessary.

MSHA notes that under the previous standard, there was no written

maintenance program required nor were records required. MSHA believes

that experience under both the previous and existing standards

demonstrates that, with the addition of paragraph (e), maintenance and

calibration is appropriately addressed in the final rule and safety is

not reduced.

Several commenters agreed with the proposal for a ``trained''

person to maintain air quality detectors and measurement devices. These

commenters suggested that the trained person be defined as a person

designated by the operator who has received training through experience

in maintenance of the instrument, has been trained by an experienced

person, or one who has received training by or through the instrument

manufacturer. MSHA has not adopted this suggestion since the operator

should have some flexibility as to the mode of training. The

requirement that the person performing the maintenance must be trained

is intended to mean that the person be capable of doing the required

maintenance, not that they receive a specific course of instruction in

what to do.

Commenters suggested that maintenance and calibration requirements

should parallel those proposed under Sec. 75.342 for machine-mounted

methane monitors. They suggested that, because the detectors and

monitors perform similar functions, the requirements should be similar.

The final rule does not adopt this suggestion. The methane monitoring

instruments under this standard and those governed by Sec. 75.342 are

subject to different mining conditions. For example, machine-mounted

monitors must be calibrated and maintained underground, on the

equipment on which they are installed and on working sections. This

calibration must also be scheduled within production timetables.

Handheld detectors and measurement devices, however, are removed from

the mine and are maintained and calibrated in surface environments.

Calibration and maintenance of handheld detectors is usually done

during shifts when the instruments are rotated out of service. Thus

machine-mounted monitors are calibrated and maintained under more

strenuous conditions than handheld detectors.

One commenter suggested that written records of all maintenance and

calibration should be required. The commenter further suggested that:

Each operator submit a written maintenance program to MSHA for approval

and provide a copy to the miner's representative; the written program

specify training to be provided; records be completed by the person

performing maintenance and be countersigned by the mine foreman within

24 hours; and that records be maintained for one year and be made

available to MSHA and the representative of the miners. These

additional requirements were not included in the proposal and are not

adopted in the final rule. The requirements contained in the final rule

adequately address and are appropriately related to the concerns

relative to maintenance, calibration, permissibility, and the general

condition of air quality detectors and measurement devices.

Section 75.321 Air Quality

The primary function of a mine ventilation system is twofold, to

remove hazardous gases such as methane, and to provide miners with an

respirable environment in areas where they are required to work or

travel. As discussed in the introductory section of this preamble,

Sec. 75.321 of the existing standard was stayed by the United States

Court of Appeals for the District of Columbia Circuit as it pertains to

bleeder entries. The final rule, in

[[Page 9776]]

Sec. 75.321, addresses acceptable levels of oxygen and carbon dioxide

in areas of a mine, including areas of a bleeder entry, where persons

are required to work or travel.

Paragraph (a)(1) continues a basic air quality requirement that has

been in place since 1970 that air in areas where persons work or travel

contain at least 19.5 percent oxygen and not more than 0.5 percent

carbon dioxide, and the volume and velocity of the air current in these

areas be sufficient to dilute, render harmless, and carry away

flammable, explosive, noxious, and harmful gases, dusts, smoke, and

fumes. Paragraph (a)(2) applies the same requirement for oxygen, 19.5

percent, for the air in areas of bleeder entries and worked-out areas

where persons work or travel. The final rule does not require the

carbon dioxide level of 0.5 percent to be applied to bleeder entries

and worked-out areas. Rather paragraph (a)(2) requires that the carbon

dioxide levels in the air in bleeder entries and worked-out areas where

persons work or travel not exceed 0.5 percent time-weighted average

(TWA) and 3.0 percent short-term exposure limit (STEL).

MSHA interpreted former Sec. 75.301 to require at least 19.5

percent oxygen and no greater than 0.5 percent carbon dioxide in

bleeder systems where persons work or travel. It was MSHA's intent that

existing Sec. 75.321 would necessitate compliance with these levels

where persons would be exposed in bleeder entries and in worked-out

areas. However, the application of this provision to bleeders and

worked-out areas was stayed by the United States Court of Appeals

pending the outcome of litigation addressing the promulgation of the

existing rule. MSHA continues to believe that providing necessary air

quality is essential to protect miners and examiners whenever they work

or travel in bleeder entries and worked-out areas. Therefore, the final

rule includes a new provision specifying that the air in bleeder

entries and worked-out areas where persons work or travel contain at

least 19.5 percent oxygen, and that carbon dioxide not exceed 0.5

percent TWA and 3.0 percent STEL. A TWA is the time-weighted average

concentration for a normal 8-hour workday and a 40-hour workweek. A

STEL is the maximum time-weighted average concentration to which miners

can be exposed for a continuous period of up to 15 minutes. Commenters

noted an error in the preamble to the proposal with respect to the time

an individual can be exposed to concentrations between the TWA and the

STEL. MSHA intends to apply TWA and STEL levels in a manner consistent

with the Air Quality rulemaking. The levels for carbon dioxide in the

final rule for areas where persons work or travel in bleeder entries

and worked-out areas are identical to the levels contained in MSHA's

proposed Air Quality standards for coal and metal and nonmetal mines

and the 1992 Threshold Limit Values (TLVs) as specified by the American

Conference of Governmental Industrial Hygienists (ACGIH).

Some commenters suggested that other changes be included in the

final rule. First, they recommended that the permissible minimum oxygen

level for bleeders and worked-out areas be lowered from 19.5 percent to

18 percent. Second, they suggested that the requirements that apply to

bleeders and worked-out areas be expanded to include airways associated

with bleederless mining areas. The rationale given for this second

recommendation was that the conditions in these airways are similar to

bleeders. In light of the ongoing Air Quality rulemaking, MSHA is not

at this time clarifying existing Air Quality standards except those for

worked-out areas and bleeder entries.

Commenters for the most part agreed with the change relative to

carbon dioxide although one commenter indicated that there was no need

for any standard. Bleeder entries and worked-out areas are required to

be traveled or evaluated at least weekly. Generally, this is done by a

person traveling alone who is often required to be in the bleeder

entries or worked-out areas for an extended period. The purpose of this

standard is to protect miners, not to regulate air quality where

persons are not exposed. Therefore, if examinations are performed

remotely or if persons making the examination can otherwise remain in

air that meets the requirements of the standard, oxygen and carbon

dioxide levels at bleeder connectors and bleeder evaluation points

would not have to meet the concentrations required by the final rule.

According to the National Institute for Occupational Safety and

Health (NIOSH) of the U.S. Department of Health and Human Services

(NIOSH Respirator Decision Logic, May 1987), 19.5 percent oxygen

provides an adequate amount of oxygen for most work assignments and

incorporates a safety factor. Also according to NIOSH, the safety

factor is needed because oxygen-deficient atmospheres offer little

warning of danger. In the NIOSH publication, ``A Guide to Safety in

Confined Spaces,'' (page 4), a chart is presented that indicates that

19.5 percent oxygen is the minimum level for safe entry into an area,

and that at a level of 16 percent, judgement and breathing are

impaired. The American National Standards Institute (ANSI), in ANSI

Z88.2-1992, ``American National Standard for Respiratory Protection''

recognizes that at 16 percent oxygen there is an impairment in the

ability to think and pay attention, and a reduction in coordination.

ANSI recognizes that at 19 percent oxygen there are some adverse

physiological effects.

The need for regulating the oxygen level where persons work or

travel in bleeder entries is illustrated by two mining accidents. One

of these accidents resulted in the death of a mine examiner and the

second resulted in the near death of two individuals, one of whom was a

mine examiner. Mine examiners are, through training and experience, the

individuals best able to identify the hazards associated with

irrespirable atmospheres. The first accident occurred at the Arclar

Mine in Equality, Illinois in 1989. Prior to implementation of the

existing standard, a mine examiner entered a worked-out area that was

posted with a danger sign and was asphyxiated. Under the existing

regulation, ventilation or sealing of this area, rather than posting,

would be required. Because the area was not sealed, the existing

regulation would require the area to be examined during the weekly

examination. The final rule would require that the route of travel for

the examiner contain at least 19.5 percent oxygen. Had the final rule

been in place when the examiner entered the worked-out area, the

accident may have been avoided.

The second accident, although not in a bleeder entry or worked-out

area, is illustrative of what can happen when individuals, including

mine examiners, are subjected to oxygen deficient air. In 1983 at the

Bird No. 3 Mine in Riverside, Pennsylvania, an assistant mine foreman,

a certified person, entered the mine for the purpose of conducting an

examination. After traveling approximately 1100 feet, the examiner

became dizzy, noticed that his flame safety lamp had extinguished and

withdrew approximately 200 feet where he sat down and apparently became

unconscious. A second individual upon entering the area in search of

the examiner also became dizzy but was able to withdraw to a location

that was not oxygen deficient. When the mine examiner regained

consciousness, his cap lamp battery had discharged and he traveled in

total darkness until he encountered a mine rescue team. Air samples

collected in the area where the mine examiner first became dizzy

[[Page 9777]]

indicated an oxygen level of about 16.8 percent, while other samples

collected nearby indicated oxygen concentrations of nearly 20 percent.

Because mine examiners are required to work or travel in areas

where oxygen-deficient air could occur without warning, and they

normally travel and work alone, there must be a requirement that

provides them the protection necessary for the performance of their

duties under these conditions. It is important that the level for

oxygen be established above that identified as resulting in impaired

judgement because it is essential that individuals traveling in these

areas remain highly alert. The hazards that can exist in bleeder

entries and worked-out areas include elevated methane levels, poor

footing, loose and unstable roof, and water accumulations. For this

reason, the final rule adopts a minimum level of oxygen of 19.5 percent

as recommended by NIOSH.

MSHA is also concerned with the effects of other gases often found

in bleeder entries. Section 75.322 of the existing regulation limits

the concentration of noxious or poisonous gases to the current (1971)

TLV's as adopted and applied by the ACGIH. Section 75.322 specifically

excludes carbon dioxide since it is covered by Sec. 75.321. However, so

the mining public will clearly understand the application of the

regulation, the final rule establishes a separate standard for carbon

dioxide levels for areas where persons work or travel in bleeder

entries and worked-out areas. The levels set by the final rule, 0.5

percent TWA and 3.0 percent STEL, when considered in conjunction with

the requirements of Sec. 75.322 and the requirement for oxygen, will

provide persons working or traveling in these areas with a safe and

healthful working environment. MSHA recognizes that the effects of

carbon dioxide are both chronic and acute and, therefore, sets both a

TWA and a STEL. NIOSH, in recommending a standard for carbon dioxide,

also recognized this and recommended a similar approach. The NIOSH

recommendation, made in a Criteria Document published in 1976, proposed

a TWA concentration of 1.0 percent and a ceiling value of 3.0 percent

not to exceed 10 minutes. In making this recommendation, NIOSH

recognized that there are additive stress effects of increased carbon

dioxide concentrations and exercise. As support for this, the NIOSH

document cites research that showed that healthy, trained subjects

exposed to 2.8 to 5.2 percent carbon dioxide at maximum exercise levels

experienced respiratory difficulty, impaired vision, severe headache,

and mental confusion; three subjects collapsed.

During rulemaking on the proposed air quality standard, NIOSH

recommended a 0.5 percent TWA and a 3.0 percent STEL. NIOSH made a

similar recommendation to the Occupational Safety and Health

Administration during that Agency's permissible exposure limit

rulemaking. Given the work environment in bleeder entries and worked-

out areas, as described earlier, MSHA believes that the regulatory

approach to bleeders and worked-out areas provided by the final rule is

necessary and appropriate. In addition to examiners, other miners may

be required to work in the bleeder entries and worked-out areas,

performing duties such as installing roof support, pumping water,

recovering materials or adjusting ventilation. The levels established

in the final rule would provide these miners with the necessary

protection.

Section 75.323 Actions for Excessive Methane

Section 75.323 establishes the actions that must be taken when

methane reaches certain levels. Methane is the most dangerous gas

encountered by miners working underground. When the level of methane

reaches 5.0 percent it is explosive. Section 75.323 generally

establishes action levels below this lower explosive limit to permit

appropriate actions to be taken by mine operators in order to prevent

an explosion.

The final rule adopts the proposal for Sec. 75.323. In doing so, it

revises paragraphs (b)(1)(ii), (c)(1), and (d)(2)(i) of the existing

standard. The rule clarifies that corrective actions at specified

methane levels must be taken ``at once'' and provides that actions for

excessive methane include areas where mechanized mining equipment is

being installed or removed. MSHA believes that final rule Sec. 75.323

increases the protection afforded by the existing standard.

Initially, the need for clarification was raised during

informational meetings and subsequent discussions after publication of

the existing rule. As discussed below, the final rule retains the

language of the proposal which is identical to the wording of the

previous standard.

Some commenters indicated that delays in remedial actions to reduce

methane were being experienced at some mines. These commenters

attributed delays to the deletion of the phrase ``at once'' in the

existing standard. These commenters also suggested that the phrase ``at

once'' conveys the proper sense of urgency to correct the condition.

Other commenters stated that the addition of the phrase ``at once''

does nothing to improve health or safety. MSHA has included the phrase

in the final rule for clarity.

Methane poses a significant hazard to miners when it is permitted

to accumulate without corrective action being taken quickly. MSHA has

always intended that corrective changes be made at once. The final rule

revises paragraphs (b)(1)(ii), (c)(1) and (d)(2)(i) to require that

these changes be made ``at once,'' the phrase used in former

Secs. 75.308 and 75.309.

Some commenters stated that the proposal, if literally enforced,

would necessitate changes to be made before the cause or source of the

increase in methane can be investigated. Other commenters stated that

approvals must be obtained for many ventilation changes and that some

changes require extended periods of time to complete. Operators may

take those actions necessary to abate imminent dangers or hazardous

conditions, or to safeguard persons and equipment. A part of this

action would be a determination of the cause of the problem. MSHA knows

of no case where an operator has been prohibited from a necessary

correction for a methane problem pending a plan approval. However, in

cases where intentional changes are made which could materially affect

the safety and health of miners, approval is required before resumption

of normal work if the changes affect the information approved in the

mine ventilation plan. MSHA recognizes that some ventilation changes

take time to accomplish and interprets the phrase ``at once'' as

meaning that the work of making the necessary change to reduce methane

levels begins immediately.

One commenter questioned how the phrase ``at once'' would apply to

a methane feeder which is encountered despite an appropriate and well

thought out ventilation change. MSHA recognizes that methane feeders

may be encountered unexpectedly. As long as a mine operators takes

action as required by the standard, they will be in compliance.

One commenter suggested that some MSHA personnel were improperly

interpreting methane excursions above 1.0 percent to be violations of

the standard. The commenter seemed to suggest the regulations should

provide that the actions specified in Sec. 75.323 for excessive methane

do not apply to concentrations detected on machine-mounted methane

monitors. Other commenters indicated that the standard requires

unnecessary ventilation

[[Page 9778]]

changes in response to instantaneous increases caused by excessive

methane liberation. MSHA recognizes that instantaneous methane monitor

readings for machine mounted monitors may occasionally reach or exceed

1.0 percent. Usually, these are short-lived and the monitor reading

quickly falls below 1.0 percent, even before the machine operator can

react. However, consistent monitor readings of 1.0 percent or more

indicate a problem and should cause appropriate changes and

adjustments. Repeated short duration increases above 1.0 per cent

should also be cause for concern and may necessitate changes or

adjustments to ventilation.

With respect to paragraphs (b)(1), (b)(2), and (c)(1) some

commenters stated that the mere presence of methane does not constitute

a violation of a mandatory health and safety standard. MSHA agrees. In

this context, one commenter suggested replacing the word ``present''

with ``detected.'' The commenter continued that an operator cannot

possibly correct a methane problem until it has been detected, that the

rule should reflect realistic expectations, and that the current term

``present'' is meaningless. MSHA agrees that a methane problem cannot

be corrected unless it has been detected and that the mere presence of

methane does not constitute a violation. Only the failure to properly

respond once being made aware of the presence of methane in excess of

allowable levels is a violation. The standard requires that an operator

properly conduct an examination; and if methane over 1.0 percent or 1.5

percent is found, as applicable, corrective action must be taken at

once.

When 1.0 percent or more methane is present in a working place, an

intake air course, or an area where mechanized mining equipment is

being installed or removed, paragraph (b)(1)(i) of the final rule

requires all electrical, diesel, and battery- powered equipment in the

affected working place, intake air course, or other area, except for

intrinsically safe AMS, to be deenergized or shut off. Deenergizing or

shutting off of this equipment protects miners by preventing this

equipment from providing ignition sources.

One commenter suggested that non-intrinsically safe AMS equipment

should be permitted to run under battery power when 1.0 percent or more

methane is encountered. The commenter stated that the benefit derived

through the system's operation outweighs the hazard of the non-

intrinsically safe system. The commenter continued that since the

batteries will deplete quickly, little hazard would result, or in the

alternative, each battery outstation could be monitored for methane and

automatically trip at some set methane level. The final rule does not

include this suggestion. Where excessive methane concentrations

necessitate that power be deenergized, information from continued

operation of the non-intrinsically safe system would not outweigh the

potential ignition hazard. To permit operation of a non- intrinsically

safe system in areas known to contain excessive levels of methane would

be a departure from accepted, effective, and long standing safety

practice.

Several commenters objected to the requirement in paragraph

(b)(1)(iii) that prohibits any work in the affected area until the

methane is reduced to less than 1.0 percent. Commenters questioned

whether the standard would prohibit an operator from taking steps to

reduce the methane. The language must be given a reasonable

interpretation and should be considered in context of the preceding

requirement in paragraph (ii) that ``changes or adjustments shall be

made at once * * * ''

These requirements are virtually identical to those found in the

previous standard which was in effect for over 20 years. MSHA is

unaware of any instance where an operator was prohibited from

correcting methane problems by such an application of the standard.

Some commenters suggested adding a phrase to paragraph (b)(1)(iii)

to read, ``No work other than removal of the accumulation shall be

permitted * * * '' Similarly, MSHA believes that the suggested change

is unnecessary and has not adopted it. MSHA experience indicates that

the rule is well understood and has been properly applied.

Other commenters thought that the standard, as proposed, would

cause hasty, ill-advised changes to be made and would prohibit an

investigation into the cause or source of the methane problem which

could result in phased-in corrections. MSHA agrees that operators

should seek long term solutions and should fully investigate the cause

or source of methane accumulations. Investigation and long term

corrections are not prohibited by the rule. However, the final rule

does require that certain actions be undertaken at once to correct the

short term or acute safety hazards resulting from accumulations of

methane.

If 1.5 percent or more of methane is present in a working place, an

intake air course, or an area where mechanized mining equipment is

being installed or removed, paragraph (b)(2) of the final rule requires

persons to be withdrawn from the affected area. The presence of methane

in these areas can pose a significant risk to miners and therefore

their withdrawal from the affected area is essential to their safety.

Paragraph (b)(2) also requires that all electric power to equipment in

affected areas be disconnected at the power source. This prevents

accidental energization of equipment and removes power from cables and

circuits which may also be ignition sources. No other work is permitted

in the affected area until the concentration of methane is less than

1.0 percent. A conforming change is also made to paragraph (b)(2) by

adding ``mechanized'' before mining equipment for consistency with

other provisions of the rule.

Comments were received which objected to the (b)(2)(ii) requirement

that except for intrinsically safe AMS, electrically powered equipment

in the affected area shall be disconnected at the power source. Some

commenters suggested that this equipment should be simply

``deenergized.'' These commenters stated that there was no need to

disconnect the power source, that this could require belt drives,

pumps, etc. to be physically disconnected where permanent connections

have been made, which could result in a major unnecessary operation.

MSHA has not adopted this suggested revision. MSHA issues numerous

citations and orders for damaged power cables, trailing cables, and

splices where the conductors are badly damaged or exposed. Each of

these citations and orders represents the presence of a potential

ignition source. Power cables would remain energized under these

conditions as would be the case if the commenters' suggestion were

adopted.

There are several aspects of Sec. 75.323 which were not proposed

for revision, but for which comments were received. Comments were

received relative to the 1.0 percent action level in intake air

courses. Commenters contended that Congress established an immutable

methane limitation of 0.25 percent in intakes. Commenters stated that

because Congress had expressly limited intakes passing openings to

abandoned areas to 0.25 percent methane, that implicitly, all intakes

were limited to 0.25 percent methane. However, the commenter then

suggested adopting an intake action level for methane of 0.5 percent.

MSHA notes that the methane levels were not proposed for revision and

are not being revised under the final rule. The commenters, however,

should refer to a discussion of this issue included in the

[[Page 9779]]

preamble to the existing rule dated May 15, 1992.

If 1.5 percent or more methane is present in return air, paragraph

(d)(2)(i) would require changes or adjustments be made ``at once'' to

the ventilation system to reduce the concentration of methane. Because

of the hazards presented by accumulations of methane, MSHA believes

that changes or adjustments should be made immediately and be made

independent of the mine ventilation plan in the interest of safety.

MSHA recognizes that some changes take time to complete. If operators

begin ``at once'' to make the necessary changes and adjustments, they

will be in compliance with the standard.

MSHA received comments relative to Sec. 75.323 which, although were

outside the scope of the rulemaking, demonstrate an incorrect

understanding of the existing rule. The limitations on methane content

and the associated actions required when excessive methane is

encountered are important components of a safety program to protect

underground miners. Therefore, several of these comments will be

addressed so that the mining community will better understand these

standards.

First, one commenter objected to the existing requirements in

Sec. 75.323(d). The commenter incorrectly stated that paragraph (d)

permits normal operations with 1.5 percent methane in working places.

Methane limits in working places and intake air courses is limited by

Sec. 75.323(b). Paragraph (b) specifies actions if 1.0 percent methane

is present, and withdrawal if 1.5 percent is present. Similarly,

Sec. 75.323(c) limits methane between the last working place on a

working section and where that split of air meets another split of air

to 1.0 percent and requires withdrawal at 1.5 percent. Paragraph (d)

modifies the requirement for that portion of the return split outby the

section loading point and has no effect on methane either in working

places or between the last working place and the point in the return

opposite the loading point.

One commenter indicated a preference for the language used in a

previous MSHA regulation, Sec. 75.308-1. The previous standard

restricted the changes or adjustments to increasing the quantity or

improving the distribution of air in the affected working place to an

extent sufficient to reduce and maintain the methane to less than 1.0

percent. The existing rule establishes a performance standard that

allows for several methods of compliance. One acceptable method of

compliance is to limit the rate of production of coal to permit the

existing ventilation system to maintain the level of methane below 1.0

percent. In all cases, however, increasing the quantity or distribution

of air continues to be an accepted means of reducing methane levels. No

safety benefit would be derived from disallowing reduced coal

extraction rates as a means of maintaining methane levels under 1.0

percent.

The final rule retains the language of proposed

Secs. 75.323(b)(1)(i), 75.323(b)(1)(iii), and 75.323 (b)(2)(i) and

(b)(2)(ii) which is identical to the wording of the existing standards.

An in-depth discussion of the reproposal of provisions concerning the

installation and removal of mechanized mining equipment is presented in

the General Discussion section of this preamble.

Section 75.324 Intentional Changes in the Ventilation System

This section addresses the precautions that must be taken when a

significant change is made to the ventilation system. MSHA did not

propose any change to existing Sec. 75.324 and is not making any

revisions in the final rule.

Questions had been raised concerning the language, ``materially

affect the safety or health of persons in the mine'' that appears in

the existing standard. The phrase is important in that it identifies

those ventilation changes that require approval of the MSHA district

manager under Sec. 75.370(c). MSHA regards it as impractical to follow

a ``cookbook'' approach to identifying what will or will not require

approval. Each particular circumstance is to be reviewed by the

operator on its own merits. To illustrate the Agency's expectations,

the following is a list of some examples of what MSHA considers

intentional changes that would materially affect the safety or health

of miners. These examples are not meant to include all possibilities,

but are meant to provide some general guidance: adding a new shaft;

bringing a new fan on line; changing the direction of air in an air

course; changing the direction of air in a bleeder system; shutting

down one fan in a multiple fan system; starting a new operating section

with ventilating quantities redistributed from other sections of the

mine; changing entries from intakes to returns and vice versa; and any

change that affects the information required by Sec. 75.371, Mine

ventilation plan; contents.

Comments were specifically solicited on issues raised in the

preamble discussion to the proposal. In response, written comments were

received from one commenter. These comments were reinforced by several

speakers at the public hearings. Other commenters indirectly referred

to Sec. 75.324 and stated that the phrase, ``materially affect the

safety or health of persons in the mine'' is accepted and understood by

the mining community.

One commenter suggested that the person designated by the operator

to supervise ventilation changes should be a certified person that is

knowledgeable of the mine's ventilation system. The results of changes

to a complex ventilation system are not always easy to predict, and for

that reason caution must be used when making significant changes to one

air split or several air splits. The balance of splits can be affected

and may result in air reversals, dead air spaces, or insufficient air

flow in critical areas. For this reason, such changes must be evaluated

by a certified person examining the affected areas to determine that

the areas are safe before production is resumed. Therefore, the Agency

believes that it is to be an unnecessary burden to also have

ventilation changes supervised by a certified person. Thus, the

suggestion of the commenter has not been adopted in the final rule.

This commenter also suggested that the provisions of Sec. 75.324

should apply to all intentional changes which alter the air current in

any section or area of the mine by 10 percent or more, or by 9,000 cfm

or more, whichever is less and that such change be considered to affect

the entire mine. The commenter recommended the miners' representative

be afforded the right to accompany the certified person to evaluate the

effects of the ventilation change and that a preshift examination of

the mine be conducted to assure that the mine is safe before electric

power is restored.

The commenter also suggested that a record be maintained of all

ventilation changes to include the names of all persons involved with

the change, the date and time of the change, and results and locations

of air quality and quantity measurements taken both before and after

the change. The commenter stated that the record should be made in an

approved book within 24 hours of the change and that the record should

be signed and countersigned. Finally, the commenter recommended that

the mine ventilation map should be updated immediately after the

ventilation change is made and that within 24 hours of the change, the

updated map should be made available to the miners' representative and

a copy sent to the district manager. Section 75.370(c) requires that

any change to the ventilation system that alters the main

[[Page 9780]]

air current or any split of the main air current in a manner that could

materially affect the safety or health of the miners, or any change to

the information required in Sec. 75.371 shall be provided to and

approved by the district manager before implementation. The final rule

requires that this information be provided to the miners'

representative at least 5 days before submittal to the district manager

(See Sec. 75.370 for full discussion). MSHA believes that this

provision provides necessary protection for miners.

One commenter stated that the standard is reactive and that MSHA

routinely cites mine operators after a methane explosion or ignition.

MSHA believes that the standard is designed to assure that operators

are proactive and develop plans that prevent hazardous conditions. The

Agency anticipates that with the clarification provided through this

rulemaking, operators will obtain MSHA approval prior to making

intentional ventilation changes that materially affect the safety and

health of miners, thereby preventing potentially hazardous conditions.

When questions arise as to whether an anticipated change requires prior

approval, MSHA is available to provide guidance as to whether approval

is necessary.

Section 75.325 Air Quantity

The quantity of air in cubic feet per minute (cfm) is an important

measure of underground coal mine ventilation. It is essential for

miners' health and safety that each working face be ventilated by a

sufficient quantity of air to dilute, render harmless, and carry away

flammable and harmful dusts and gases produced during mining. An

insufficient quantity of air at a working face could permit methane to

accumulate and lead to an explosion. Section 75.325 generally

establishes the quantities of air that must be provided and the

locations underground where these quantities must be provided.

Section 75.325(d) requires that areas where mechanized mining

equipment is being installed or removed be ventilated and that the

minimum quantity of air and the ventilation controls necessary to

provide these quantities be specified in the approved mine ventilation

plan. The final rule adds the word ``minimum'' to the phrase,

``quantity of air'' that appears in the existing standard and the

proposal. The existing standard was reproposed without change. An in-

depth discussion of the reproposal of provisions concerning the

installation and removal of mechanized mining equipment is presented in

the General Discussion section of this preamble.

Only a few comments were received that were specific to paragraph

(d). One commenter discussing Sec. 75.371(r) suggested that the

quantity of air required by Sec. 75.325(d) to be specified in the plan

should represent the ``minimum'' quantity to be provided and that the

location specified should be identified as typical so as to give the

mine the flexibility to adapt to conditions. This comment is consistent

with MSHA's intent for the proposal and helps to clarify it. Therefore,

the word ``minimum'' has been inserted into the final rule in both

Sec. 75.371(r) and paragraph (d) of Sec. 75.325. Obviously, mine

operators can have air quantities which exceed the minimum specified in

the mine ventilation plan. MSHA agrees conceptually with a comment that

the ventilation scheme shown in the plan should be representative of

the method of ventilation to be used. However, MSHA does not adopt this

comment because the plan must also be specific enough so that the

operator, the miners, the representative of miners, and MSHA are

assured that the areas are being adequately ventilated.

Other commenters suggested that the total quantity of air to be

delivered to a longwall needs to be specified in the mine ventilation

plan. In support of the suggestion the commenter stated that the

inclusion of the word ``total'' recognizes that some mines may use belt

air at the set up or tear down phase while some intake air may be

diverted to ventilate bleeders, battery chargers or compressors and,

therefore, the total quantity of air being delivered to the longwall

face should be the figure with which MSHA is concerned. The commenter

stated further that the recommendation recognizes that conditions vary

greatly from mine to mine, coal seam to coal seam, even from one

longwall panel to the next panel of the same mine. The commenter added

that while a specified amount of air can be delivered to a recovery

face, and pressure can be placed on the gob, it is impossible to

guarantee a specified volume or velocity of air at the recovery point.

MSHA agrees that the total air quantity provided to a recovery face

is of importance; however, the distribution of this air is also

important. The volume of air being delivered to the longwall face

during equipment removal is important because of the types of

activities that occur (e.g. cutting and welding and the operation in

some cases of considerable numbers of diesel powered vehicles) and the

fact that it is along the face that the majority of miners work and

where an ignition hazard exists. It is important to know exactly how

areas where mechanized equipment is being installed or removed will be

ventilated. Therefore, this suggestion has not been included and the

rule.

Commenters were concerned about the ventilation of a longwall face

prior to the first gob fall. This type of concern should be handled

through the mine ventilation plan. Paragraph (d) only deals with areas

were mechanized mining equipment is being installed or removed and not

where mining is in progress.

Section 75.330 Face Ventilation Control Devices

The final rule adds a new paragraph (c) adopting the proposal

language. The new paragraph (c) requires that when line brattice or any

other face ventilation control device is damaged to an extent that

ventilation of the working face is inadequate, production activities in

the working place are required to cease until necessary repairs are

made and adequate ventilation is restored. MSHA notes that before

issuing a citation for a violation of this provision, an inspector

would normally be expected to measure the air quantity to determine

whether adequate ventilation is being maintained.

Some commenters considered the proposed regulation redundant since

operators must already maintain minimum air quantities at the face,

thereby making repairs necessary to maintain the required quantity.

Face ventilation controls are a critical feature of reliable

ventilation. As such, maintaining these controls in good condition and

making repairs necessary to restore ventilation is sound safety

practice. To do less invites increased risk of a methane ignition and

elevated respirable dust. Also on a practical level most miners on a

working section do not have a means of measuring air quantities.

However, miners can determine when ventilation controls are damaged

appreciably and are likely to adversely affect the air quantity.

One commenter indicated that entire working sections might be shut

down to repair a ventilation control at any one face with no

corresponding safety benefit. The final rule provides that ``production

activities in the working place shall cease'' until adequate

ventilation is restored. Unless elevated methane levels or some other

problem existed, the entire section would not be shut down for repair

of a ventilation control.

Some commenters asserted that controls may be slightly damaged

while still maintaining quantities in excess of

[[Page 9781]]

the requirements at the face. Similarly, commenters worried that

numerous citations would be issued based solely on the appearance of

the controls, even though the minimum required face air quantities are

exceeded. These commenters stated that the only reliable indicator is

an air measurement.

MSHA agrees that the only precise indicator of air quantity is a

measurement. Accordingly, MSHA anticipates that noncompliance decisions

will be based on air measurements which show ``ventilation of the

working place is inadequate.'' However, ventilation controls which are

in poor condition are likely to cue an inspector to conduct an air

measurement.

Other commenters generally expressed the view that the requirements

of Sec. 75.330, even considering the proposed revision, are inadequate

to fully address the issue of face ventilation. According to these

commenters, additional requirements are needed, including: proper

installation and maintenance criteria for face ventilation control

devices, requirements for providing devices continuously from the last

open crosscut to the working face, immediate repair of these devices if

damaged by a fall or otherwise, providing sufficient space between the

line curtain and the rib and maintaining the area free of obstructions,

and minimizing leakage while providing installations which permit

traffic to pass without adversely affecting ventilation. Further, the

commenters asserted that only cumulatively can the desired result be

obtained through these requirements and that additional requirements

would empower individual miners to take corrective actions when needed.

Each of these suggestions is a desirable ventilation practice which

MSHA supports. However, the final rule is not intended to set detailed

standards for the installation of ventilation control devices. Instead,

the rule addresses minimum requirements for face air quantities and

requires the face ventilation system used to deliver these quantities

to be maintained.

Some commenters indicated a concern about so-called ``deep-cut''

mining wherein continuous miners, by remote control, develop cuts from

25 to 60 feet inby permanent roof support. Commenters questioned the

adequacy of face ventilation where ventilation controls may be 30 to 50

feet from the face. Specifically, questions were raised about: whether

adequate ventilation actually reaches the face in ``deep cuts'' to

dilute methane; whether more frequent air measurements are needed;

whether methane checks are representative of face concentrations;

maximum feasible cut depth and ventilation device distance; respirable

dust in ``deep cuts;'' proper maintenance of ventilation control

devices; how ventilation is maintained after the continuous miner is

withdrawn from the cut; roof bolter ventilation; and differences

between scrubber systems and sprayfan systems. Another commenter noted

that historically most roof fall fatalities have occurred within 25

feet of the face. This commenter asserted that the deep-cut mining

system helps to resolve this problem and reduce exposure. The commenter

continues that to prohibit any variation from the 10 foot line curtain

distance requirement would adversely affect safety of the miners

working in the area.

MSHA agrees that each of these issues is important. The appropriate

vehicle to address these specific concerns is the mine ventilation plan

required by existing Sec. 75.370. The mine ventilation plan provides

the necessary latitude to address the diversity of mining conditions

found throughout the country. Details of each system must be shown in

the plan and must be specific to the conditions at each mine where such

a system is employed. Also, MSHA's review and approval of mine plans

includes an onsite investigation to evaluate the system and to assess

the adequacy of the specified plan parameters. In addition, inspectors

routinely evaluate the suitability of the mine ventilation plan during

regular mine inspections.

The commenter's concerns about methane checks in ``deep cuts'' is

addressed by the final rule Sec. 75.362(d)(2) which requires that

methane tests be made ``at the face.'' This new requirement will assure

that measurements are taken at the location where the hazard is most

likely to occur. Testimony received at the public rulemaking hearings

indicated that technology exists in the form of extendable probes that

can be used to take these measurements, without putting miners at

additional risk from fall of ground.

Section 75.332 Working Sections and Working Places

Working sections and working places are the areas of a coal mine

with the greatest amount of activity and the largest concentration of

workers. They are the location of the greatest number of potential

ignition sources. They therefore harbor the greatest risk of accidents

such as methane ignitions and explosions and equipment fires. Section

75.332 addresses the ways these areas are ventilated to reduce the

likelihood of an accident on one section impacting another section,

with deadly consequences. Generally, Sec. 75.332 provides that each of

these areas must be ventilated with a separate split of fresh air that

has not been used to ventilate another working area or an area where

mining has ceased if this area cannot be examined. When ventilated in

this manner, the products from a fire on one section will not

contaminate another section and methane in worked-out areas will not be

carried to working sections by the ventilating air stream.

The final rule provides that each working section and each area

where mechanized mining equipment is being installed or removed, shall

be ventilated by a separate split of intake air directed by overcasts,

undercasts or other permanent ventilation controls. The final rule

adopts the language of proposed Sec. 75.332(a)(1), which is identical

to existing Sec. 75.332(a)(1). An in-depth discussion of the reproposal

of provisions concerning the installation and removal of mechanized

mining equipment is presented in the General Discussion section of this

preamble.

Several commenters responded to Sec. 75.332(a)(1). Some commenters

suggested that the standard be revised to permit the installation of

mechanized mining equipment in either the return or intake air courses

of working sections provided the air had not been used to ventilate any

worked-out areas, areas where pillars have been recovered, or bleeder

systems. The commenters maintained that prohibiting the installation of

longwall equipment on the same split of air as a developing unit delays

the installation of a mining system. The commenters further observed

that this mining equipment consists mainly of steel conveyor sections

and roof supports that contain a 95 percent water-based hydraulic fluid

which does not burn. Therefore, according to these commenters, longwall

mining equipment can safely be installed on the intake side of an

active mining unit and, with monitoring, in the return air course of an

active mining unit.

The safety benefits of using separate splits of air to provide

ventilation are well established. A primary benefit of such a provision

is to protect workers down-wind from being put at risk by events up-

wind from their location. Among the most serious of these risks is

miners being overcome by the products of combustion or an explosion.

In Miner's Circular 50, ``Explosions and Fires in Bituminous-Coal

Mines'' published by the Bureau of Mines in

[[Page 9782]]

1954, the authors state that when air travels a long path through a

mine, it gradually becomes depleted of oxygen and may become so

contaminated with other gases that it no longer is healthful, or it may

accumulate enough explosive gas to present an explosion hazard. The

authors go on to state that when the air is divided into several

splits, each traveling a short path, better air can be furnished to

each group of persons in the mine. Further, if a local explosion or

fire should occur, the poisonous gases evolved may be confined to one

section and the force of the explosion and the gases may kill all the

persons in that particular section but may not affect other sections of

the mine. According to the authors, when a mine is ventilated by a

continuous current of air, the miners on the return side of an

explosion or fire probably will be killed or overcome by the poisonous

gases and that judicious splitting of the air is a safeguard against

this eventuality.

Similarly, Stefanko states in the 1973 edition of the Society of

Mining Engineers (SME) Engineering Handbook that splitting the air is

recognized as being necessary for safety and presents only minimal

power cost.

The commenters implied that because longwall mining equipment is

largely noncombustible, this danger is minimized for workers down-wind

on an active mining section. This reasoning overlooks the fact,

however, that the installation of a longwall is labor-intensive,

involving cutting and welding in the presence of methane and coal, as

well as machinery operating under load. These conditions add

contaminants to the ventilating current, and increase the possibility

of a fire or explosion. Likewise, a longwall being installed on the

return side of an active mining section would expose the miners doing

the installation to the dust and gases, and the results of a fire or

explosion, from the section. Even with monitoring, miners would be put

at risk as their opportunities for escape would be limited. For these

reasons, the final rule does not adopt the commenters'' suggestion.

One commenter also suggested that ``approved ventilation controls''

be required instead of specifying that overcasts, undercasts or other

permanent ventilation controls be used to direct intake air. The

commenter explained that this would allow operators the flexibility of

submitting plans that allow the use of temporary controls in some

instances.

Temporary controls to split air are not as reliable as permanent

controls. The first explosion at the Scotia Mine in 1976 which killed

15 miners, was due in part to the improper use of a temporary

ventilation control where a permanent control (i.e., an overcast)

should have been used. More recently, the explosion that occurred

during the set up of a longwall at the Golden Eagle Mine in 1991 which

injured 11 miners involved the removal of two permanent ventilation

controls and the replacement of these controls with temporary controls.

As these and other accidents illustrate, the ventilation controls that

deliver air to working areas are vitally important to miners'' safety.

Therefore, the final rule requires that these controls be permanent in

nature and not temporary.

Another commenter indicated that the use of temporary controls

would lower worker exposure to hazards by not requiring repeated

handling of permanent control materials which can be heavy. Proper

handling practices and modern materials can reduce the risk of injuries

associated with handling construction materials. MSHA considers these

risks lower than the dangers of using temporary controls in lieu of

permanent controls.

Section 75.333 Ventilation Controls

The primary means for directing air from the outside, through the

mine openings, to the working areas and back to the surface is through

the use of ventilation controls: either permanent controls, such as

stoppings (walls), overcasts or undercasts (air bridges), and doors, or

temporary controls, such as line brattice (curtains). Permanent

ventilation controls are designed for long term use while temporary

controls are intended for use on a short term basis. In general,

Sec. 75.333 specifies where each type of control can be used and how

each permanent control is to be constructed. It is essential that

ventilation controls be correctly constructed, maintained, and properly

located to provide ventilation to working sections and other areas

where it is needed to dilute methane, respirable coal mine dust and

other contaminants, and provide miners with a safe and healthful work

environment.

The final rule revises paragraphs (a), (b)(1), (b)(3), (b)(4) and

(e)(1) of existing Sec. 75.333, and adds a new paragraph (h). Revisions

to paragraphs (a) and (e)(1) address the durability of stoppings, while

the revisions to (b)(1), (b)(3) and (b)(4) address ventilation controls

required when continuous haulage systems are used. New paragraph (h)

requires all permanent ventilation controls, including seals, to be

maintained to serve the purpose for which they were built.

The use of continuous haulage systems, particularly in low seam

coal mines, is becoming more common. The final rule specifically

addresses continuous haulage systems in paragraphs (b)(1), (b)(3) and

(b)(4) of the rule and clarifies where temporary controls are an

acceptable means of ventilation control when these systems are used.

Continuous haulage systems utilize mobile bridge conveyors or similar

mechanisms to transport coal directly from a continuous mining machine

to a low profile belt. As the continuous mining machine moves from

place to place, the continuous haulage system slides back and forth

along a low profile conveyor belt using a ``dolly'' or other travel

mechanism. The low profile conveyor belt then transports the coal to

the section conveyor belt.

The existing rule permits the use of temporary ventilation controls

in lieu of permanent ventilation controls to separate continuous face

haulage systems from return, intake, and primary escapeway entries in

rooms developed 600 feet or less from the centerline of the entry from

which the rooms were developed. This practice is consistent with

longstanding MSHA policy, which recognizes that these rooms are used

for a short duration and the minimum air quantity must be maintained

regardless of the controls used.

Existing paragraph (b)(1) allows temporary controls to separate

intake and return air courses in rooms driven 600 feet or less from the

centerline of the entry from which the room was developed. The final

rule adds to existing paragraph (b)(1) the proposed language clarifying

that the use of temporary controls in these rooms is also acceptable

when continuous haulage systems are used. This change responds to

commenters who point out that the rooms in which the continuous haulage

systems are installed are continuously attended by the operators of the

system and an immediate response to any safety related problem with the

system or the ventilation controls would be expected. Commenters also

noted that two or three rooms are often concurrently developed using a

continuous haulage system and the life of the actively developing rooms

is often less than three days. As a result of this short life, mining

in these rooms is often completed before construction of permanent

controls is finished. Also, access to the continuous haulage system is

required through crosscuts for maintenance and operation of the system.

Under paragraphs (b)(3) and (b)(4) the proposal would have required

belt and

[[Page 9783]]

intake separation to the outby travel point of the dolly and belt and

primary escapeway separation to the inby most travel point. Commenters

indicated confusion because of the distinction between intake and

primary escapeway separation and believed that conflicts would exist.

Commenters also suggested that the language proposed to address the use

of temporary ventilation controls for continuous haulage systems was

confusing and contradictory. The final rule revises the requirements of

proposed paragraphs (b)(3) and (b)(4) to respond to these comments.

Paragraph (b)(3) of the final rule retains the requirement that

permanent controls be provided to separate belt conveyor haulageways

from intake air courses when the air in the intake air course is used

to provide air to active working places. The final rule also retains

the proposed provision that when continuous haulage systems are used in

rooms less than 600 feet from the centerline of the entry from which

the rooms were developed, temporary stoppings or other temporary

ventilation controls may be built and maintained to provide the

required separation.

Commenters stated that new technology may result in continuous

haulage systems with the outby point of travel of the dolly extending

considerably beyond the 600 feet distance. The commenters noted that

such an extended length of temporary controls could result in

unanticipated adverse consequences for the ventilation system, and

suggested that a maximum distance of 300 feet outby the inby point of

travel of the dolly be established for the use of temporary ventilation

controls. MSHA agrees that extensive use of temporary ventilation

controls can create problems, including excessive leakage and the

possible short circuiting of air. The final rule, therefore, limits the

distance that temporary controls may be used to separate continuous

haulage systems from intake air courses, including the primary

escapeway. The final rule permits temporary controls to be used from

the point of deepest penetration of the conveyor belt entry to the most

outby point of travel of the dolly or 600 feet, whichever distance is

the less. As a result, 600 feet is the maximum linear distance of entry

in which temporary controls may be used for separation of air courses.

The 600 feet would be measured as a straight-line distance from the

point of deepest penetration in the conveyor belt haulage entry. This

approach comports with the 600 foot limit for the use of temporary

stoppings in rooms and allows a reasonable use of temporary ventilation

controls with continuous haulage systems, while preserving the

integrity of the ventilation system. At present, MSHA would expect that

the most outby point of travel of the dolly would govern since MSHA is

not aware of any continuous haulage systems which travel more than 600

feet outby the point of deepest penetration.

Paragraph (b)(4) of the final rule continues to require permanent

stoppings or other permanent ventilation control devices to separate

the primary escapeway from the belt and trolley haulage entries, as

required by Sec. 75.380(g). Commenters suggested that for the purposes

of Sec. 75.380(g), the definition of loading point in proposed

paragraph (b)(4) be revised to be the outby point of travel of the

dolly as opposed to the inby point of travel. The final rule adopts

this suggestion and requires separation by permanent stoppings to be

maintained to the outby point of travel of the dolly or 600 feet from

the point of deepest penetration, whichever distance is less, to

separate the haulage entry from the primary escapeway. The provisions

of Sec. 75.380(g) continue to allow the district manager to require a

greater or lesser distance for this separation.

In response to questions about acceptable construction methods and

materials for permanent ventilation controls (excluding seals) MSHA

proposed eliminating the definition of ``durable'' in paragraph (a) and

to modify paragraph (e)(1). The proposal would have required these

controls to be constructed in a manner and of materials that result in

a construction that has been tested and shown to have a minimum

strength of 39 pounds per square foot as tested under ASTM E72-80

Section 12--Transverse Load-Specimen Vertical, load only (ASTM E72-80).

The 8-inch hollow-core concrete block stopping with mortared joints, to

which all other constructions were tied under the definition of durable

in the existing standard, has been tested and shown to have a minimum

strength of 39 pounds per square foot.

MSHA received numerous comments questioning the validity of the

ASTM E72-80 test for determining acceptability of underground

ventilation controls. Commenters questioned the appropriateness of a

strength requirement of 39 pounds per square foot and the relevance of

this value to the in-mine conditions. After review, MSHA continues to

believe that use of the ASTM E72-80 test to determine that the relative

strength of a ventilation control construction is appropriate and the

final rule retains this standard. However, MSHA sees merit in some of

the suggestions made by commenters. Commenters suggested that some

constructions can not be tested according to the ASTM test, some

constructions that are widely used in coal mines do not meet the 39

pound per square foot threshold, and the ASTM test can only be run at a

limited number of locations nationwide.

After reviewing all of the comments received and based on

experience with various construction methods and materials used for

permanent ventilation controls since the inception of the Mine Act, the

final rule recognizes traditionally accepted construction methods for

permanent ventilation controls, and retains the ASTM test for new

materials and methods. Controls made with new materials or methods must

be comparable in strength to controls made with traditionally accepted

materials or methods.

Since the inception of the Mine Act, a number of traditionally

accepted construction methods have performed adequately and have served

their intended function of separating air courses. These traditionally

accepted construction methods are: 8-inch and 6-inch concrete blocks

(both hollow-core and solid) with mortared joints; 8-inch and 6-inch

concrete blocks dry-stacked and coated on both sides with a strength

enhancing sealant suitable for dry-stacked stoppings; 8-inch and 6-inch

concrete blocks dry-stacked and coated on the high pressure side with a

strength enhancing sealant suitable for dry-stacked stoppings; steel

stoppings (minimum 20-gauge) with seams sealed using manufacturer's

recommended tape and with the tape and perimeter of the metal stopping

coated with a suitable mine sealant; and lightweight incombustible

cementatious masonry blocks coated on the joints and perimeter with a

strength enhancing sealant suitable for dry-stacked stoppings. In

addition, 4-inch concrete blocks may be used in the above applications

in seam heights less than 48 inches. Tongue and groove 4-inch concrete

blocks coated on both sides with a strength enhancing sealant suitable

for dry-stacked stoppings may be used in coal seams of any height. The

sealants referred to in this paragraph would be applied in the

thickness recommended by the manufacturer. MSHA maintains a list of

sealants which may be used for the above applications. This list is

available at each MSHA District Office. The final rule would continue

to permit these traditionally accepted construction

[[Page 9784]]

methods to be acceptable for the construction of ventilation controls.

For new construction methods or materials other than those used for

the traditionally accepted constructions identified above, the final

rule requires that the strength be equal to or greater than the

traditionally accepted in-mine controls. Tests may be performed under

ASTM E72-80 Section 12--Transverse Load-Specimen Vertical, load only,

or the operator may conduct comparative in-mine tests. In-mine tests

must be designed to demonstrate the comparative strength of the

proposed construction and a traditionally accepted in-mine control.

As with the existing rule, the final rule would require, in

paragraph (e)(1)(ii), that all overcasts, undercasts, shaft partitions,

permanent stoppings, and regulators, installed after November 15, 1992,

be constructed of noncombustible material. Also, like the existing

standard, the final rule lists materials that would be suitable for

these controls. The final rule would also continue to prohibit

ventilation controls installed after November 15, 1992, from being

constructed of aluminum.

Paragraph (h) of the proposal would have required that all

permanent ventilation controls, including seals, be maintained to serve

the purpose for which they were built. The final rule retains proposed

paragraph (h) with one revision. One commenter stated that the

paragraph should require all ventilation controls, including temporary

controls, to be maintained to serve the purpose for which they were

built. Given the importance of temporary controls devices in providing

for adequate ventilation, the final rule requires all ventilation

controls, both permanent and temporary, including all doors and seals,

to be maintained to serve the purpose for which they were built. This

standard applies to all ventilation controls, regardless of the

construction date.

Relative to seal maintenance, MSHA does not intend that the

maintenance requirement be applied to seals located within another

sealed area. Additionally, the rule does not apply to seals which have

become consumed within a gob area which is ventilated and evaluated in

a manner approved in the mine ventilation plan.

One commenter raised several questions concerning what MSHA would

consider to be an acceptable temporary stopping. MSHA has not defined

the term ``temporary ventilation control'' in the rule. The commenter

stated that, in the preamble to the proposal, MSHA refers to ``properly

constructed'' temporary stoppings but does not include a standard for

construction or installation and maintenance of temporary stoppings.

The commenter adds that temporary ventilation controls are a source of

potential leakage and are often susceptible to damage from roof and rib

falls and from mobile equipment. The commenter also refers to several

accidents where failure to maintain permanent or temporary ventilation

controls was a critical factor in the accident.

MSHA agrees that to properly direct the flow of air and provide for

adequate face ventilation, temporary controls, as well as all permanent

ventilation controls, must be installed and maintained in an adequate

manner to control leakage. MSHA has accepted as temporary controls,

check curtains or other flame- resistant material approved by MSHA that

are constructed and installed in such a manner to minimize leakage. As

required by paragraph (h) of this section of the final rule, these

controls must be maintained to serve the purpose for which they were

built.

Section 75.334 Worked-Out Areas and Areas Where Pillars Are Being

Recovered

Worked-out areas, areas where coal extraction has been completed,

can pose deadly hazards to miners, including an explosive methane

accumulation, irrespirable atmosphere, and the possibility of fire from

spontaneous combustion. Section 75.334 establishes the requirements for

ventilation of these areas to mitigate these hazards. In general,

Sec. 75.334 requires that following mining, these areas are to be

sealed or ventilated. Section 75.334 also specifies the requirements

for evaluating the effectiveness of the ventilation of worked-out areas

so operators can determine that the ventilation system is functioning

as intended.

The final rule revises paragraph (e) of the existing Sec. 75.334.

Existing paragraph (e) requires that each mining system be designed so

that worked-out areas can be sealed. The final rule adds to paragraph

(e) the proposed requirement that the location and sequence of

construction of proposed seals be specified in the approved mine

ventilation plan. Improper location and sequencing of seal construction

can have a dangerous effect on mine air quality and ventilation. As the

proper location and sequence of construction of seals is a mine-by-mine

determination, the mine ventilation plan provides the most workable

mechanism by which to assure proper air quality and ventilation of the

mine.

Several commenters objected to including seal construction sequence

as part of the information to be submitted for approval in the mine

ventilation plan. Their rationale was that mining conditions change and

could result in a change in the sequence of seal construction. The

construction might then be delayed while approval for the change is

obtained. These commenters suggested that in some cases, delays in seal

construction could result in a hazard to miners. Other commenters

stated that the sequence of construction of seals is more appropriately

and more easily shown on the mine ventilation map required by

Sec. 75.372. Another commenter stated that the sequence of construction

should be subject to approval because the placement of seals if

improperly installed can cause adverse effects on the ventilation

system and gob gases. MSHA is sensitive to the concern that a delay in

approval could result in a hazard to miners and, as explained in the

preamble discussion of Sec. 75.370, if a delay in seal construction

would result in a hazard to miners the review and approval of the plan

can be expedited.

MSHA agrees with the commenter that the location and sequence of

seal construction may be more easily, that is, more clearly shown on

the mine map required by Sec. 75.372 than in the written text of the

plan submitted under Sec. 75.371. The existing standard permits

appropriate information required under Sec. 75.371 to be shown on the

map required by Sec. 75.372. The effect is that the information both

appears on the ventilation map and in the ventilation plan and is

subject to approval. The discussion of Sec. 75.371(bb) further

addresses this point.

Spontaneous combustion is the process through which coal or other

materials self heat by the absorption of oxygen. Paragraph (f) of

Sec. 75.334 addresses mines with a demonstrated history of spontaneous

combustion and those located in coal seams determined to be susceptible

to spontaneous combustion. Paragraph (f) requires that the approved

mine ventilation plan for these mines specify the measures that will be

used to detect methane, carbon monoxide, and oxygen concentrations

during and after pillar recovery, and in worked-out areas where no

pillars have been recovered; the actions that will be taken to protect

miners from the hazards of spontaneous combustion; and, if a bleeder

system will not be used, the methods that will be used to control

spontaneous combustion, accumulations of methane-air mixtures, and

other gases, dusts, and fumes in the worked-out area.

[[Page 9785]]

Through meetings with various segments of the mining community,

MSHA became aware of a concern that paragraph (f) of existing

Sec. 75.334 may have been promulgated without the public being provided

the opportunity to adequately comment. Although MSHA believes that

existing paragraph (f) was promulgated properly, the Agency reproposed

paragraph (f) with wording identical to that used in existing

Sec. 75.334. The purpose of the reproposal was to assure MSHA received

and considered all pertinent comments.

Several commenters to the existing rule suggested that bleeder

systems should not be required for all mines. These commenters stated

that in some mines the practice of ventilating worked-out areas

increases the risk of spontaneous combustion by supplying oxygen to

combustion-prone materials in these areas. They also requested that the

final rule promulgated in 1992 include provisions to address

spontaneous combustion. MSHA acknowledged the need to reduce the flow

of oxygen to areas where there is a likelihood of spontaneous

combustion, and included in the 1992 rule requirements for mine

ventilation plans to address spontaneous combustion in mines with a

demonstrated history of this hazard or mines that are located in coal

seams determined to be susceptible to spontaneous combustion.

Experience gained through application of the existing standard has

demonstrated that a limited number of mines have experienced

spontaneous combustion problems. Studies by the Bureau of Mines have

identified the volatile properties of coal seams and have determined

that certain seams are susceptible to spontaneous combustion. The final

rule is directed to mines in these seams.

MSHA is not suggesting that all coal mines will meet the test to

show susceptibility to spontaneous combustion. A demonstrated history

or the determination of susceptibility to spontaneous combustion is a

prerequisite to the applicability of paragraph (f). While it is true

that all coal oxidizes when exposed to air, this fact is not sufficient

to make the determination that a coal seam is susceptible to

spontaneous combustion. MSHA would expect that absent a demonstrated

history of spontaneous combustion in a mine, an operator would provide

the necessary data to demonstrate that the mine is susceptible to

spontaneous combustion so that the provisions of paragraph (f) should

apply. A number of methods are used to determine the self heating

tendency of a coal.

However, MSHA is also mindful that some mines that have a

spontaneous combustion p

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