Respiratory Protection and Controls To Restrict Internal Exposures

NUCLEAR REGULATORY COMMISSION

10 CFR Part 20

RIN 3150-AF81

Respiratory Protection and Controls To Restrict Internal

Exposures

AGENCY: Nuclear Regulatory Commission.

ACTION: Proposed rule.

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SUMMARY: The Nuclear Regulatory Commission (NRC) is proposing to amend

its regulations regarding the use of respiratory protection and other

controls to restrict internal exposure to radioactive material. The

proposed amendments are intended to make these regulations more

consistent with the philosophy of controlling the sum of internal and

external radiation exposure, reflect current guidance on respiratory

protection from the American National Standards Institute (ANSI), and

make the requirements less prescriptive without reducing worker

protection. The proposed amendments would provide greater assurance

that worker exposures will be maintained as low as is reasonably

achievable (ALARA) and that recent technological advances in

respiratory protection equipment and procedures are reflected in NRC

regulations and are thus clearly approved for use by licensees.

DATES: Submit comments by September 30, 1998. Comments received after

this date will be considered if it is practical to do so, but the

Commission is able to assure consideration only for comments received

on or before this date.

ADDRESSES: Send comments to: Secretary, U.S. Nuclear Regulatory

Commission, Washington, DC 20555-0001, Attention: Rulemakings and

Adjudications Staff.

The NRC staff specifically requests comment on whether the

technical aspects of the rule should be addressed through alternative

approaches other than the proposed rule, such as a simple

[[Page 38512]]

performance-based rule with a Regulatory Guide endorsing ANSI standards

to permit a more rapid regulatory response by the NRC to future

technical developments and changes in industry consensus standards.

In addition to comments on this proposed rule, the NRC staff

requests specific comments and suggestions regarding the content and

scope of a planned revision of NUREG-0041, ``Manual of Respiratory

Protection Against Airborne Radioactive Materials.''

Hand deliver comments to: 11555 Rockville Pike, Rockville, Maryland

between 7:30 am and 4:15 pm Federal workdays.

You may also provide comments via the NRC's interactive rulemaking

web site through the NRC home page (http://www.nrc.gov). This site

provides the availability to upload comments as files (any format), if

your web browser supports that function. For information about the

interactive rulemaking site, contact Ms. Carol Gallagher, (301) 415-

5905; e-mail [email protected]

Certain documents related to this rulemaking, including comments

received and the environmental assessment and finding of no significant

impact, and NUREG-0041, may be examined at the NRC Public Document

Room, 2120 L Street NW. (Lower Level), Washington, DC. These same

documents also may be viewed and downloaded electronically via the

interactive rulemaking website established by NRC for this rulemaking.

Single copies of the environmental assessment and finding of no

significant impact and the regulatory analysis may be obtained from

Antoinette Walker, Office of Nuclear Reactor Regulation, U.S. Nuclear

Regulatory Commission, Washington, DC 20555, telephone: (301) 415-1282.

Single copies of the draft revision of Regulatory Guide 8.15,

``Acceptable Programs for Respiratory Protection,'' which is related to

this rulemaking, may be obtained by writing to: U.S. Nuclear Regulatory

Commission, Printing and Graphics Branch, Washington, DC 20555-0001; or

by fax at (301) 415-5272.

FOR FURTHER INFORMATION CONTACT: Alan K. Roecklein, Office of Nuclear

Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC

20555-0001, telephone (301) 415-3883; email [email protected]

SUPPLEMENTARY INFORMATION:

I. Background

A major revision of 10 CFR Part 20, ``Standards for Protection

Against Radiation,'' was published on May 21, 1991 (56 FR 23360).

Although the NRC was aware that certain provisions of Subpart H and

Appendix A to Part 20 were out of date and did not reflect new

technology in respiratory devices and procedures, minimal changes were

made because an ANSI standard was being prepared that was expected to

provide state-of-the-art guidance on acceptable respiratory protection

devices and procedures. The NRC decided to address further revisions to

Subpart H and Appendix A to Part 20 when the ANSI guidance was

complete.

In response to public comments on the proposed 10 CFR Part 20, the

NRC made several changes to Subpart H in the May 21, 1991, rule to make

it consistent with the new philosophy and science underlying the new

Part 20. The new Subpart H required that the practice of ALARA apply to

the sum of internal and external dose, permitted correction of both

high and low initial intake estimates if subsequent, more accurate

bioassay measurements gave different results, and clarified that a

respiratory protection program consistent with Subpart H is required

whenever respirators are used to limit intakes of radioactive material.

After 10 CFR Part 20 was revised, ANSI Z88.2-1992, ``American

National Standard for Respiratory Protection'' was approved for

publication by the American National Standards Institute. This document

provides an authoritative consensus on major elements of an acceptable

respiratory protection program, including guidance on respirator

selection, training, fit testing, and assigned protection factors

(APF). Consistent with the publication of ANSI Z88.2-1992 the NRC is

proposing these changes to Subpart H of Part 20 to make the regulations

less prescriptive without reducing worker protection.

II. Summary of the Proposed Changes

The Commission is proposing to amend Sec. 20.1003, Secs. 20.1701

through 20.1704 in Subpart H, ``Respiratory Protection and Controls to

Restrict Internal Exposure in Restricted Areas,'' of 10 CFR Part 20,

and Appendix A to Part 20, ``Protection Factors for Respirators''.

In Sec. 20.1003, Definitions, definitions are proposed for Assigned

protection factor (APF), Disposable respirator, Fit check, Fit factor

and Fit test. These added definitions are needed to add clarity to the

proposed regulations at Secs. 20.1701 through Secs. 20.1705.

In Sec. 20.1701, Use of process or other engineering controls, the

word ``decontamination'' would be added to the list of examples of

process or engineering controls that should be considered for

controlling the concentration of radioactive material in air. The

intent is to encourage licensees to consider decontamination,

consistent with maintaining total effective dose equivalent (TEDE)

ALARA, to reduce resuspension of radioactive material in the work place

as a means of controlling internal exposure instead of using

respirators.

Section 20.1702 would be revised by adding a footnote (2) to

Sec. 20.1702(c) to clarify that if a licensee performs an ALARA

analysis to determine whether or not respirators should be used, safety

factors other than radiological may be taken into account. A reduction

in the TEDE for a worker is not reasonably achievable if an attendant

increase in the workers' industrial health and safety risk would exceed

the benefit obtained by the reduction in the radiation risk. Regulatory

Guide 8.15 (DG-8022) and NUREG-0041 will address in more detail how

factors such as heat, discomfort, reduced vision, etc., associated with

respirator use, might reduce efficiency or increase stress thereby

increasing external dose or health risk. Considerable licensee judgment

is necessary in determining an appropriate level of respiratory

protection in many cases.

Section 20.1703 states the requirements for licensees who use

respiratory protection equipment to limit intake of radioactive

material. The use of a respirator is by definition intended to limit

intakes of airborne radioactive materials, unless the device is clearly

and exclusively used for protection against non-radiological airborne

hazards. Whether or not credit is taken for the device in estimating

doses, it is the use of the respiratory protection device to limit

intake of radioactive material and associated physiological stresses

that would activate the requirements of Sec. 20.1703. Thus Sec. 20.1703

can be viewed as defining the minimum respiratory protection program

expected of any licensee who assigns or permits the use of respirators.

In Sec. 20.1703(a), the phrase ``pursuant to Sec. 20.1702'' would

be deleted. This language has been misinterpreted to mean that an

approved respiratory protection program is not needed if respirators

are used when concentrations of radioactive material in air are already

below values that define an airborne radioactivity area. This is not

the case and the proposed Sec. 20.1703 should make it clear that, if a

licensee uses respiratory protection equipment

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``to limit intakes,'' the provisions of Sec. 20.1703 apply as a

minimum.

In Sec. 20.1703(a)(1), (proposed Sec. 20.1703(a)), licensees are

permitted to use only respirators that have been tested and certified

``or had certification extended'' by NIOSH. The words ``or had

certification extended'' would be deleted because all these extensions

have expired and no new extensions will be granted.

In Sec. 20.1703(a)(2), (proposed Sec. 20.1703(b)), licensees are

permitted to apply for authorization to use equipment that has not been

tested or certified by NIOSH and ``has not had certification extended

by NIOSH/MSHA.'' The words ``has not had certification extended by

NIOSH/MSHA'' would be deleted because all these extensions have expired

and no new extensions will be granted. The words ``to the NRC'' are

added to make it clear that applications for authorized use of

respiratory equipment are to be submitted to the Commission.

In Sec. 20.1703(a)(3), (proposed Sec. 20.1703(c)), paragraphs

(c)(1) through (5) are retained as presently codified with the

exception of some minor editing and that paragraph (c)(4) would be

reworded to improve clarity, reorder priorities, and bring together in

one paragraph all of the elements of the required written procedures.

Paragraph (c)(5) would be revised to clarify that the worker's medical

evaluation for using non-face sealing respirators occurs prior to first

field use rather than prior to first fitting (as required for tight

fitting respirators) because fit testing is not needed for these types.

A new Sec. 20.1703(c)(6) would be added to require fit testing

prior to first field use of tight fitting, face sealing respirators and

periodically thereafter. This proposed change would clarify when and

how often fit testing is required. The licensee would specify a

frequency of retest in the procedures, not to exceed 3 years. This

differs from the ANSI recommendation of annual fit testing. The NRC

believes that if a licensee is alert to physiological changes that

might affect an individual's ability to wear a respirator safely,

annual fit testing is an excessive burden. A requirement to wear

properly fitted respirators is currently in the footnotes to Appendix A

to Part 20 and would be moved to the body of the rule. Several general

programmatic requirements currently found in footnotes to Appendix A to

Part 20 would be moved to the text of the rule where they more

appropriately belong and to ensure that they are not overlooked by

licensees.

The new Sec. 20.1703(c)(6) would also codify existing NRC staff

guidance and ANSI recommendations regarding the test ``fit factors''

that must be achieved in order to use the APFs and the frequency of fit

testing. Specifically, fit testing with ``fit factors'' 10

times the APF would be required for negative pressure devices. A fit

factor 100 would be required for all tight fitting face

pieces used with positive pressure, continuous flow, and pressure-

demand devices. This provision is intended to maintain a sufficient

margin of safety to accommodate the greater difficulty in maintaining a

good ``fit'' under field and work conditions as compared to fit test

environments.

The proposed Sec. 20.1703(c)(6) would also require retesting at a

frequency not to exceed 3 years. Guidance in the proposed revision of

Regulatory Guide 8.15 (DG-8022) on the frequency of fit testing

suggests a retest period not to exceed 3 years. Currently, most

licensees perform annual fit testing. The proposed 3-year retesting

does not agree with the ANSI recommendation for annual retesting. The

NRC believes that a 3-year interval between fit tests is adequate to

protect workers under normal circumstances, given adequate surveillance

of workers for physiological changes. Regulatory Guide 8.15 discusses

what constitutes an adequate surveillance program, including being

alert to circumstances such as significant weight loss or gain, facial

changes, etc., that would suggest more frequent fit testing. Transient

workers might require more frequent retesting because continuous

monitoring for physiological changes is impracticable.

The current Sec. 20.1703(a)(4), which lists requirements for

licensees to issue a written policy statement, would be deleted because

the NRC believes that this policy statement is not needed. This change

is proposed because all of the elements required to be in the policy

statement are already found in Part 20 and in the requirement for

licensees to have and implement written procedures (see proposed

Sec. 20.1703(c)(4)).

Section 20.1703(a)(6) would become Sec. 20.1703(e) and would be

clarified and expanded to emphasize the existing requirements that

provisions be made for vision correction, adequate communications, and

low-temperature work environments. In order to comply with these

requirements, a licensee would need to take into account the effects of

restricted vision and communication limitations as well as the effects

of adverse environmental conditions on the equipment and the wearer.

The NRC considers the inability of the respirator wearer to read

postings, operate equipment and/or instrumentation, or properly

identify hazards to be an unacceptable degradation of personnel safety.

A requirement for licensees to consider low-temperature work

environments when selecting respiratory protection devices would be

added to the proposed Sec. 20.1703(e). For example, the moisture from

exhaled air when temperatures are below freezing could cause the

exhalation valve on negative pressure respirators to freeze in the open

position. The open valve would provide a pathway for unfiltered air

into the respirator inlet covering without the user being aware of the

malfunction. Lens fogging that reduces vision in a full face piece

respirator is another problem that can be caused by low temperature.

The reference to skin protection currently found in

Sec. 20.1703(a)(6) would be deleted in the proposed Sec. 20.1703(e).

The NRC does not consider skin protection an appropriate reason for the

use of respirators (with the exception of air supplied suits).

Limitation of skin dose is currently dealt with elsewhere in the

regulations for example in Sec. 20.1201(a)(2)(ii), skin dose limit. It

may be inconsistent with ALARA to use tight fitting respirators solely

to prevent facial contamination; other protective measures such as the

use of facelets instead of respirators or decontamination should be

considered. Facial contamination may result in a less significant dose

than that received as a result of respirator use or prior

decontamination of the area.

A new Sec. 20.1703(f) would be added to bring a requirement for

standby rescue persons, currently found in a footnote in Appendix A to

Part 20, into the rule. This new paragraph would retain a requirement

for the presence of standby rescue persons whenever one-piece

atmosphere-supplying suits, or any other combination of supplied air

respirator device and protective equipment are used that are difficult

for the wearer to take off unassisted. Standby rescue workers would

also need to be in direct communication with such workers, be equipped

with appropriate protective clothing and devices, and be immediately

available to provide needed assistance in the event that the air supply

fails. Without continuous air supply, unconsciousness can occur within

seconds.

A new Sec. 20.1703(g) would move a requirement from a footnote in

Appendix A to Part 20, into the rule. This section would specify the

minimum quality of supplied breathing air, as defined by the Compressed

Gas Association (CGA) in their publication G-7.1, ``Commodity

Specification for

[[Page 38514]]

Air,'' 1989 (ANSI-CGA G-7.1, 1989), that must be provided whenever

atmosphere-supplying respirators are used. This change to recognizing

the CGA recommendations for air quality was initiated by NIOSH and

endorsed by ANSI. The quantity of air supplied, as a function of air

pressure or flow rate, would be specified in the NIOSH approval

certificate for each particular device and is not addressed in the

proposed rule.

A new Sec. 20.1703(h) is added to clarify and move a requirement

from the footnotes of Appendix A to Part 20, into the rule. This

section prohibits the use of respirators whenever any material or

substance might interfere with the seal of the respirator. The intent

of this provision is to prevent the presence of facial hair, cosmetics,

spectacle earpieces, surgeons caps, and other things from interfering

with the respirator seal and/or proper operation of the respirator.

Currently, Sec. 20.1703(b)(1) discusses selection of respiratory

protection equipment so that protection factors are adequate to reduce

intake. This paragraph permits selection of less protective devices if

that would result in optimizing TEDE. The NRC believes that this

requirement is redundant with the requirement to be ALARA. These

recommendations are being removed and will be discussed in the revised

Regulatory Guide 8.15.

The remainder of Sec. 20.1703(b)(1) would become Sec. 20.1703(i)

and be revised to incorporate the new ANSI terminology for ``assigned

protection factor'' and to retain the provision for changing intake

estimates if later, more accurate bioassay measurements show that

exposure was greater or less than initially estimated.

Current Sec. 20.1703(b)(2), specifying procedures for applying to

the NRC to use higher APFs, is renumbered as Sec. 20.1705.

Current Sec. 20.1703(c) would be removed because it requires

licensees to use as emergency devices only respiratory protection

equipment that has been specifically certified or had certification

extended for emergency use by NIOSH. This approval category no longer

exists. Acceptable types of emergency and escape equipment will be

discussed in the revisions of Regulatory Guide 8.15 and NUREG-0041.

Because only equipment approved by NIOSH or NRC can be used in the

respiratory protection program pursuant to Sec. 20.1703(a) and (b),

this provision is considered redundant.

Current Sec. 20.1703(d) would be deleted. This section currently

requires a licensee to notify in writing the director of the

appropriate NRC Regional Office at least 30 days before the date that

respiratory protection equipment is first used under the provisions of

either current Sec. 20.1703(a) or (b). All licensees who possess

radioactive material in a form that requires a respiratory protection

program are identified during the license application, amendment, or

renewal processes. Their programs would be reviewed during this

process. A 30-day notification requirement imposes a needless

administrative burden on licensees with no increase in worker health

and safety. This proposed change is considered to be a burden

reduction.

Section 20.1704(a) would be revised to clarify that ALARA

considerations are included in any restrictions imposed by the

Commission in addition to those found in Secs. 20.1702, 20.1703, and

Appendix A to Part 20 on the use of respiratory protection equipment

for the purpose of limiting exposures of individuals to airborne

radioactive materials.

Appendix A to Part 20--``Protection Factors (PF) for Respirators,''

would be modified extensively. In general, new devices are recognized,

APFs are revised to be consistent with current ANSI guidance and

technical knowledge, and the footnotes to Appendix A are moved,

deleted, revised, or adjusted so that only those necessary to explain

the table remain. Footnotes that are instructive or that facilitate

implementation of the rule would be moved to Regulatory Guide 8.15.

Several footnotes are considered to be redundant in that they reiterate

NIOSH certification criteria to be discussed in NUREG-0041 and would be

removed. Generic regulatory requirements, previously contained in

footnotes in Appendix A to Part 20 would be moved to the codified text

of Part 20.

The column headed ``Tested and Certified Equipment,'' would be

deleted. The references to Titles 30 and 42 of the CFR currently found

in this column apply primarily to respirator manufacturers and are not

very useful to NRC licensees. Instruction on how to determine if a

respirator is NIOSH approved will be provided in the revision to NUREG-

0041.

Current footnote a to Appendix A to Part 20 would be deleted

because it is considered to be redundant with air sampling requirements

and requirements for estimating possible airborne concentration

addressed in the proposed rule at Sec. 20.1703(c)(1) and

Sec. 20.1703(i).

Current footnote b, which permits the use of devices only when

nothing interferes with the seal of a face piece, would be moved to the

codified text at Sec. 20.1703(h).

Current footnote c, which defines the symbols for modes of

operation would be revised to fit the new list of respiratory devices

in Appendix A to Part 20 consistent with ANSI Z88.2-1992 and become

footnote b.

Current footnote d.1 would be removed because the essential

information regarding the meaning and use of APF is found in the

proposed rule at Sec. 20.1703(i). Further guidance regarding the

application and limitation of APFs would be provided in the revisions

of Regulatory Guide 8.15 and NUREG-0041.

Current footnote d.2(a) states that APFs are only applicable for

trained individuals who are properly fitted and for properly maintained

respirators. This footnote is redundant with the current and proposed

Sec. 20.1703 and would be removed. Adequate provisions for training,

fit-testing, and equipment maintenance are found in the proposed rule

at Sec. 20.1703(c)(4).

Current footnote d.2(b) states that APFs are applicable for air-

purifying respirators only when high-efficiency particulate filters are

used in atmospheres not deficient in oxygen and not containing

radioactive gas or vapor respiratory hazards. This statement would be

revised in proposed footnote c to say that if using a respirator with

an APF greater than 100, a filter with a minimum efficiency of 99.97

percent must be used. Further guidance will be provided in Regulatory

Guide 8.15 and NUREG-0041. The definitions of filter types and

efficiencies will be discussed in the revisions of Regulatory Guide

8.15 and NUREG-0041.

Current footnote d.2(c) states that APFs cannot be used for

sorbents against radioactive gases and/or vapors (e.g., radioiodine).

This is no longer an absolute prohibition. A provision would be made in

the new proposed footnote d for licensees to apply to the Commission

for the use of an APF greater than 1 for sorbent cartridges.

Current footnote d.2(d) restates part of the NIOSH approval

criteria for air quality for supplied air respirators and self-

contained breathing apparatus. This requirement would be changed to

reflect the fact that air quality standards derive from ANSI's

recognition of the Compressed Gas Association guidance, and moved to

the rule at Sec. 20.1703(g). Air quality is discussed further in

Regulatory Guide 8.15 and NUREG-0041.

The current footnote e makes it clear that the APFs for atmosphere-

supplying respirators and self-contained breathing

[[Page 38515]]

apparatus are not applicable in the case of contaminants that present a

skin absorption or submersion hazard. This statement would be retained

in footnote d in the proposed Appendix A to Part 20. However, the

current exception provided for tritium oxide requires correction in

that the effective protection factor cannot exceed 3, rather than 2 as

stated. This correction would be made in footnote d of the proposed

Appendix A to Part 20. A discussion of the basis for this change will

be found in revised NUREG-0041.

Current footnote f observes that canisters and cartridges for air

purifying respirators will not be used beyond service-life limitations.

This observation restates a NIOSH approval criterion and is more

appropriate to guidance than to the regulations. This footnote would be

deleted. Service life limitations are addressed in Regulatory Guide

8.15 and NUREG-0041.

The current footnote g addresses four issues. The first limits the

use of half-mask face piece air purifying respirators to ``under-chin''

types only. This limitation would be retained as footnote (f) to the

proposed new Appendix A to Part 20. The only type of face piece

eliminated by this requirement is the so-called ``quarter-mask'' which

seals over the bridge of the nose, around the cheeks and between the

point of the chin and the lower lip. These devices exhibit erratic

face-sealing characteristics, especially when the wearer talks or moves

his/her mouth.

The second issue precludes this type of respirator if ambient

airborne concentrations can reach instantaneous values greater than 10

times the pertinent values in Table 1, Column 1 of Appendix B to Part

20. Because respirator assignment is now based on TEDE, ALARA, and

other consideration, this part of current footnote g would be deleted

from the proposed footnote f.

The third issue precludes the use of this type of respirator for

protection against plutonium or other high-toxicity materials. Half-

mask respirators, if properly fitted, maintained and worn, provide

adequate protection if used within the limitations stated in the NIOSH

approval and in the rule. The NRC finds no technical or scientific

basis for continuing this prohibition in view of current knowledge and

proposes to remove it.

Finally this footnote requires that this type mask be tested for

fit (user seal check) before each use. This provision would be removed

because the proposed Sec. 20.1703(c)(3) would require a user to perform

a fit check (e.g., negative pressure check, positive pressure check,

irritant smoke check) each time a respirator is used.

Current footnote h provides several conditions on air-flow rates

necessary to operate supplied air hoods effectively. Because all of

these requirements are elements of the NIOSH approval criteria, they

are redundant and would be removed. However, these NIOSH requirements

will be discussed in the revision to NUREG-0041.

Current footnote I specifies that appropriate protection factors be

determined for atmosphere-supplying suits based on design and

permeability to the contaminant under conditions of use. Conditions for

the use of these devices are retained in footnote g to the proposed

revision of Appendix A to Part 20. Guidance on the use of these devices

would be included in the revision to Regulatory Guide 8.15. Current

footnote I also requires that a standby rescue person equipped with a

respirator or other apparatus appropriate for the potential hazards,

and communications equipment be present whenever supplied-air suits are

used. This requirement would be deleted from the footnotes to Appendix

A to Part 20 and moved to the body of the rule at Sec. 20.1703(f).

Current footnote j states that NIOSH approval schedules are not

available for atmosphere-supplying suits. This information and criteria

for use of atmosphere supplying suits would be addressed in footnote g

to the proposed Appendix A to Part 20. Note that an APF is not listed

for these devices. Licensees would be permitted to apply to the

Commission for the use of higher APFs in accordance with

Sec. 20.1703(b).

Current footnote k permits the full face piece self-contained

breathing apparatus (SCBA), when operating in the pressure-demand mode,

to be used as an emergency device in unknown concentrations. This

provision would be retained in footnote I to the proposed Appendix A to

Part 20 and full face piece SCBA operating in positive pressure,

recirculating mode is added.

Current footnote l requires quantitative fit testing with a leakage

less than 0.02 percent for the use of full face piece, positive

pressure, recirculating mode SCBA. This requirement would be removed

from the rule to be consistent with ANSI guidance and addressed in the

revision to Regulatory Guide 8.15.

Current footnote l also states that perceptible outward leakage of

breathing gas from this or any positive pressure SCBA whether open

circuit or closed circuit is unacceptable, because service life will be

reduced substantially. This provision would be retained in footnote I

to the proposed Appendix A to Part 20.

Current footnote l also requires that special training in the use

of this type of apparatus be provided to the user. The NRC believes

that the training requirement that would be retained at

Sec. 20.1703(c)(4) is adequate to assure the training necessary for the

use of SCBA devices. This element of footnote l would be removed.

Note 1 to the current Appendix A to Part 20 discusses conditions

under which the protection factors in the appendix may be used, warns

against assuming that listed devices are effective against chemical or

respiratory hazards other than radiological hazards, and states the

need to take into account applicable approvals of the U.S. Bureau of

Mines/NIOSH when selecting respirators for nonradiological hazards.

Note 1 would be retained as footnote (a) to the proposed Appendix A to

Part 20 and would be revised to reference Department of Labor (DOL)

regulations at 29 CFR 1910. The NRC believes that these conditions are

essential to the safe use of APFs and that the DOL regulations are also

applicable whenever other than radiological respiratory hazards are

present.

Note 2 to the current Appendix A to Part 20 warns that external

dose from submersion in high concentrations of radioactive material may

result in limitations on occupancy being governed by external dose

limits. This note would be retained as the second paragraph of footnote

a to the proposed Appendix A to Part 20.

In the title of Appendix A to Part 20, and throughout the proposed

rule, the term ``assigned protection factor'' (APF) is used to be

consistent with the new ANSI Z88.2-1992 terminology.

Although ANSI suggested an APF=10 for all half-mask face piece

disposable respirators, disposables that do not have seal enhancing

elastomeric components and are not equipped with two or more adjustable

suspension straps would be permitted for use but would not have an APF

assigned (i.e., no credit may be taken for their use). The NRC believes

that without these components it is difficult to maintain a seal in the

workplace. These devices have little physiological impact on the

wearer, may be useful in certain situations, and they may accommodate

workers who request respiratory protection devices as required by OSHA.

Medical screening is not required for each individual prior to use

because the devices impose very little physiological stress. In

addition, fit testing is not required because an APF is not specified

(i.e., no credit may be taken for their use). However, all other

[[Page 38516]]

aspects of an acceptable program specified in Sec. 20.1703 are required

including training of users in the use and limitations of the device.

The NRC believes that this provision allows the flexible and effective

use of these devices without imposing conditions that are

impracticable. However, for those licensees who would like to use the

ANSI recommended APF of 10, proposed footnote e to Appendix A to Part

20 would permit an APF of 10 to be used if the licensee can demonstrate

a fit factor of at least 100 using a validated or evaluated

quantitative or qualitative fit test. This requirement is appropriate

because fit testing is an implicit component of the ANSI approval

process.

The half-mask face piece respirator would continue to be approved,

but relatively new variations are referred to in the industry as

``reusable,'' ``reusable-disposable,'' ``face-piece-filtering'' or

``maintenance-free'' devices. In these devices, including those

considered to be disposables, the filter medium may be an integral part

of the face piece, is at least 99 percent efficient, and may not be

replaceable. Also, the seal area is enhanced by the application of

plastic or rubber to the face-to-face piece seal area and the 2 or more

suspension straps are adjustable. These devices are acceptable to the

NRC, are considered half masks, may be disposable, and would be given

an APF=10, consistent with ANSI recommendations.

The assigned protection factor for full face piece air purifying

respirators operating in the negative pressure mode would be increased

from 50 to 100. This change is consistent with ANSI recommendations and

industry test results. The current Appendix A to Part 20 lists a

protection factor of 50 because one design that was tested at Los

Alamos in 1975 did not meet the PF 100 criterion. This device is no

longer available.

A fit factor of 10 times the APF for negative-pressure air-

purifying respirators, which must be obtained as a result of required

fit testing under Sec. 20.1703(c)(6), is recommended by ANSI and would

be required under the proposed rule; that is, a person would have to

achieve a minimum of 1,000 on a fit test in order to use an APF of 100

in the field. Use of a fit factor of 10 times the APF effectively

limits internal dose and accounts for any respirator leakage that might

occur during workplace activities. Fit factors of 10 times the APF were

previously not required for such devices.

A new category of respirator, the loose-fitting face piece,

positive pressure (powered) air purifying type, would be included in

the proposed Appendix A to Part 20. An APF of 25 would be assigned to

this new device in accordance with ANSI Z88.2-1992.

The half-mask and the full face piece air-line respirators

operating in demand mode would be listed with APF unchanged at 5. The

NRC believes that supplied-air respirators operating in the demand mode

should be used with great care in nuclear applications. Because they

are very similar in appearance to more highly effective devices

(continuous flow and pressure-demand supplied air respirators), they

might mistakenly be used instead of the more protective devices.

The APFs for half-and full-face piece air-line respirators

operating on continuous flow would be reduced from 1,000 to 50 and from

2,000 to 1,000 respectively. The APF for a full face piece air-line

respirator operating in pressure-demand mode would be reduced from

2,000 to 1,000. These changes are based on ANSI recommendations and the

results of field measurements indicating that these devices are not as

effective as originally thought. This change would have little impact

on licensees because typical workplace concentrations encountered are

far less than 1000 times the derived air concentrations (DACs).

However, licensees may apply for higher APFs if needed and justified. A

half-mask air-line respirator operating in pressure-demand mode would

be added to Appendix A with an APF of 50 based on ANSI recommendations.

The helmet/hood air-line respirator operating under continuous flow

would be retained with the APF listed as 1,000. Current footnote h

which specifies NIOSH certification criteria for flow rates would be

removed. The criteria for air flow rates are part of the NIOSH approval

and would be addressed in the revision to NUREG-0041.

The new loose fitting face piece design is also included as an air-

line respirator operating under continuous flow. This device would be

assigned an APF of 25 in the proposed Appendix A to Part 20 consistent

with ANSI recommendations.

The air-line atmosphere-supplied suit would not be assigned an APF.

These devices have been used for many years in radiological

environments such as control rod drive removal at boiling water

reactors with no APF. These devices are primarily used as contamination

control devices, but they are supplied with air that the wearer

breathes. No problems are known to have occurred at nuclear power

plants or other NRC licensees that would disallow use of these devices.

The NRC is allowing the use of non-NIOSH-approved suits but wearers are

required to meet all other respirator program requirements in

Sec. 20.1703 except the need for a fit test. Licensees would still have

an option to apply to the Commission for higher APFs in accordance with

proposed Sec. 20.1703(b). Requirements for standby rescue persons apply

to these devices (Sec. 20.1703(f)).

In the proposed Appendix A to Part 20, APFs for SCBA devices would

remain unchanged. Use of SCBA in demand open circuit and demand

recirculating mode requires considerable caution. In the NRC's view,

the performance level and reliability of these devices is questionable.

The chance of face piece leakage when operating in the negative

pressure mode is considerably higher than when operating in a positive

pressure mode. This is especially critical for devices that could be

mistakenly used in emergency situations. Although ANSI lists high APFs

for these devices, they are not recommended by the NRC for use and

acceptable alternative devices are readily available. Footnote h

requires that controls be implemented to assure that these devices are

not used in immediately dangerous to life and health (IDLH) areas.

In proposed footnote d, a specific statement would be added to

exclude radioactive noble gases from consideration as an airborne

hazard and advising that external (submersion) dose considerations

should be the basis for protective actions. In the current rule, DAC

values are listed for each noble gas isotope. This has led some

licensees to inappropriately base respirator assignments in whole or in

part on the presence of these gases. The requirement for monitoring

external dose can be found in 10 CFR 20.1502.

The complete proposed changes to Part 20, Subpart H and Appendix A

to Part 20 are presented in the codified text section of this document.

III. Issue of Compatibility for Agreement States

In accordance with the new adequacy and compatibility policy and

implementing procedures approved by the Commission on June 30, 1997,

the proposed modifications to Secs. 20.1701 through 20.1703, and

Sec. 20.1705 have health and safety significance and Agreement States

should adopt the essential objectives of these rule modifications in

order to maintain an adequate program. Therefore, these provisions are

assigned to the ``Health and Safety (H&S)'' category. The proposed

definition of Assigned

[[Page 38517]]

Protection Factor (APF) because of its precise operational meaning, is

designated as compatibility category C to help insure effective

communication. Therefore, Agreement States should adopt the essential

objectives of this provision to avoid conflicts, duplication or gaps.

The proposed definitions of Disposable respirator, Fit check, Fit

factor and Fit test, are stated in general terms and are therefore

designated as compatibility category D, not required for purposes of

compatibility. Flexibility is also provided to States regarding

Sec. 20.1704 in how they handle imposition of additional restrictions

on the use of respiratory protection. Therefore, this provision is

designated as compatability category D. Comments are specifically

requested on whether assigning different compatibility categories to

the proposed new definitions creates any implementation problems or

inconsistencies.

Appendix A to 10 CFR Part 20 is designated as compatibility

category B because assigned protection factors (APFs) provide

acceptable levels of protection to be afforded by respirators.

Additionally, although Sec. 20.1705 permits applying for the use of

higher APFs on a case by case basis, consistency is required in APFs

that are established as acceptable in NRC and Agreement State

regulations to reduce impacts on licensees who may operate in multiple

jurisdictions.

These proposed amendments were provided to the Agreement States

during the NRC staff review process via the use of the NRC rulemaking

bulletin board and notification to the States of its availability. Two

comments were received. One suggested assigning compatibility

categories to the five new definitions, which has been done in this

proposed rule. A second noted that removal of generic requirements from

the footnotes to Appendix A greatly improved the rule.

IV. Finding of No Significant Environmental Impact: Availability

The NRC has determined under the National Environmental Policy Act

of 1969, as amended, and the Commission's regulations in Subpart A of

10 CFR Part 51, that the proposed amendments, if adopted, would not be

a major Federal action significantly affecting the quality of the human

environment and therefore, an environmental impact statement is not

required.

The proposed amendment addresses technical and procedural

improvements in the use of respiratory protection devices to maintain

total occupational dose as low as is reasonably achievable. None of the

impacts associated with this rulemaking have any effect on any places

or entities outside of a licensed site. An effect of this proposed

rulemaking is expected to be a decrease in the use of respiratory

devices and an increase in engineering and other controls to reduce

airborne contaminants. It is expected that there would be no change in

radiation dose to any member of the public as a result of the revised

regulation.

The determination of this environmental assessment is that there

will be no significant offsite impact to the public from this action.

Therefore, in accord with its commitment to complying with Executive

Order 12898--Federal Actions to Address Environmental Justice in

Minority Populations and Low-Income Populations, dated February 11,

1994, in all its actions, the NRC has also determined that there are no

disproportionate, high, and adverse impacts on minority and low-income

populations. The NRC uses the following working definition of

``environmental justice'': the fair treatment and meaningful

involvement of all people, regardless of race, ethnicity, culture,

income, or educational level with respect to the development,

implementation, and enforcement of environmental laws, regulations, and

policies. Comments on any aspect of the environmental assessment may be

submitted to the NRC as indicated under the ADDRESSES heading.

The NRC has sent a copy of the environmental assessment and this

proposed rule to every State Liaison Officer and requested their

comments on the environmental assessment.

The draft environmental assessment is available for inspection at

the NRC Public Document Room, 2120 L Street, NW. (Lower Level),

Washington, DC. Single copies of this document are available as

indicated in the ADDRESSES heading.

V. Paperwork Reduction Act Statement

This proposed rule contains amendments to reduce the information

collection requirements contained in 10 CFR Part 20 that are considered

to be insignificant (250 hours annually), when compared with the

overall requirements of the CFR Part (210, 205 hours annually). NRC

does not consider this reduction in the burden to be significant enough

to trigger the requirements of the Paperwork Reduction Act of 1995 (44

U.S.C. 3501 et seq.). Existing requirements were approved by the Office

of Management and Budget, approval number 3150-0014.

Public Protection Notification

If an information collection does not display a currently valid OMB

control number, the NRC may not conduct or sponsor, and a person is not

required to respond to, the information collection.

VI. Regulatory Analysis

The NRC has prepared a regulatory analysis for the proposed

amendment. The analysis examines the benefits and impacts considered by

the NRC. The regulatory analysis is available for inspection at the NRC

Public Document Room at 2120 L Street NW. (Lower Level), Washington,

DC. Single copies are available as indicated under the ADDRESSES

heading.

VII. Regulatory Flexibility Certification

As required by the Regulatory Flexibility Act of 1980, 5 U.S.C.

605(b), the NRC certifies that, if adopted, this proposed rule would

not have a significant economic impact on a substantial number of small

entities. The anticipated impact of the proposed changes would not be

significant because the revised regulation basically represents a

continuation of current practice. The benefit of the proposed rule is

that it would provide relief from certain reporting and recordkeeping

requirements, incorporate several ANSI recommendations for improved

programmatic procedures, and permit the use of new, effective

respiratory devices, thus increasing licensee flexibility.

The NRC is seeking public comment on the initial regulatory

flexibility certification. The NRC is seeking comment particularly from

small entities as defined under the NRC's size standards 10 CFR 2.810,

as to how the proposed regulations would affect them and how the

regulations may be implemented or otherwise modified to impose less

stringent requirements on small entities while still adequately

protecting the public health and safety. Any small entity subject to

this regulation who determines that, because of its size, it is likely

to bear a disproportionate adverse economic impact should offer

comments that specifically discuss the following items:

(a) The licensee's size and how the proposed regulation would

result in a significant economic burden or whether the resources

necessary to implement this amendment could be more effectively used in

other ways to optimize public health and safety, as compared to the

economic burden on a larger licensee;

[[Page 38518]]

(b) How the proposed regulation could be modified to take into

account the licensees' differing needs or capabilities;

(c) The benefits that would accrue, or the detriments that would be

avoided, if the proposed regulation were modified as suggested by the

licensee;

(d) How the proposed regulation, as modified, could more closely

equalize the impact of NRC regulations or create more equal access to

the benefits of Federal programs as opposed to providing special

advantages to any individual or group; and

(e) How the proposed regulation, as modified, would still

adequately protect the public health and safety.

The comments should be sent to the Secretary of the Commission,

U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. ATTN:

Rulemakings and Adjudications Staff. Hand deliver comments to 11555

Rockville Pike, Rockville, Maryland, between 7:30 am and 4:15 pm

Federal workdays.

VIII. Backfit Analysis

Although the NRC staff has concluded that some of the changes being

proposed constitute a reduction in burden, the implementation of these

and other changes will require revisions to licensee procedures

constituting a potential backfit under 10 CFR 50.109(a)(1). Under

Sec. 50.109(a)(2), a backfit analysis is required unless the proposed

rule meets one of the exceptions listed in Sec. 50.109(a)(4). This

proposed rule meets the exception at Sec. 50.109(a)(4)(iii) in that it

is redefining the level of adequate protection as regards the use of

respirators for radiological protection.

Section II, Summary of the Proposed Changes, summarizes the

proposed changes to Subpart H of 10 CFR Part 20. The reasons for making

these changes are also provided. Many of the proposed changes are

considered by the NRC to constitute a redefinition of adequate level of

protection in that they reflect new consensus technical guidance

published by the American National Standards Institute (ANSI) on

respiratory protection developed since 10 CFR Part 20, Subpart H was

published. The changes include recognizing new respirator designs and

types that were not available 20 years ago, changing the assigned

protection factors (APFs) based on new data, deleting certain reporting

requirements which are considered no longer needed for oversight of a

mature industry, and numerous procedural improvements that have been

developed and proven by respiratory practitioners.

In conclusion, the Commission believes that the proposed changes

constitute a burden reduction with the exception of the need to revise

procedures to implement the requirements. The proposed changes also

clearly redefine the level of adequate protection required for workers

who use respiratory protection and are, therefore, the type of change

for which a backfit analysis is not required under

Sec. 50.109(a)(4)(iii).

List of Subjects in 10 CFR Part 20

Byproduct material, Criminal penalties, Licensed material, Nuclear

materials, Nuclear power plants and reactors, Occupational safety and

health, Packaging and containers, Radiation protection, Reporting and

recording requirements, Special nuclear material, Source material,

Waste treatment and disposal.

For the reasons set out in the preamble and under the authority of

the Atomic Energy Act of 1954, as amended, the Energy Reorganization

Act of 1974, as amended, and 5 U.S.C. 553, the NRC is proposing to

adopt the following amendments to 10 CFR Part 20.

PART 20--STANDARDS FOR PROTECTION AGAINST RADIATION

1. The authority citation for Part 20 continues to read as follows:

Authority: Secs. 53, 63, 65, 81, 103, 104, 161, 182, 186, 68

Stat. 930, 933, 935, 936, 937, 948, 953, 955, as amended (42 U.S.C.

2073, 2093, 2095, 2111, 2133, 2134, 2201, 2232, 2236), secs. 201, as

amended, 202, 206, 88 Stat. 1242, as amended, 1244, 1246 (42 U.S.C.

5841, 5842, 5846).

2. Section 20.1003 is amended by adding the definitions Assigned

protection factor (APF), Disposable respirator, Fit check, Fit factor,

and Fit test to read as follows:

Sec. 20.1003 Definitions.

* * * * *

Assigned protection factor (APF) means the expected workplace level

of respiratory protection that would be provided by a properly

functioning respirator or a class of respirators to properly fitted and

trained users. Operationally, the inhaled concentration can be

estimated by dividing the ambient airborne concentration by the APF.

* * * * *

Disposable respirator means a respirator for which maintenance is

not intended and that is designed to be discarded after excessive

resistance, sorbent exhaustion, physical damage, or end-of-service-life

renders it unsuitable for use. Examples of this type of respirator are

a disposable half-mask respirator or a disposable escape-only self-

contained breathing apparatus (SCBA).

* * * * *

Fit check (user seal check) means a performance check conducted by

a respirator wearer to determine if the respirator is properly seated

to the face. Examples include negative pressure check, positive

pressure check, irritant smoke check, or isoamyl acetate.

Fit factor means a quantitative measure of the fit of a particular

respirator to a particular individual.

Fit test means a test, quantitative or qualitative, to evaluate the

fit of a respirator on an individual and to determine a fit factor.

* * * * *

3. Section 20.1701 is revised to read as follows:

Sec. 20.1701 Use of process or other engineering controls.

The licensee shall use, to the extent practicable, process or other

engineering controls (e.g., containment, decontamination, or

ventilation) to control the concentration of radioactive material in

air.

4. In Sec. 20.1702, paragraph (c) is revised to add the following

footnote:

Sec. 20.1702 Use of other controls.

* * * * *

(c) Use of respiratory protection equipment \2\; or

---------------------------------------------------------------------------

\2\ If the licensee performs an ALARA analysis to determine

whether or not respirators should be used, safety factors other than

radiological may be taken into consideration and the impact of the

use of respirators on workers industrial health and safety risk

should be considered.

---------------------------------------------------------------------------

5. Section 20.1703 is revised to read as follows:

Sec. 20.1703 Use of individual respiratory protection equipment.

If the licensee assigns or permits the use of respiratory

protection equipment to limit the intake of radioactive material,

(a) The licensee shall use, only respiratory protection equipment

that is tested and certified by the National Institute for Occupational

Safety and Health (NIOSH).

(b) If the licensee wishes to use equipment that has not been

tested or certified by NIOSH, or for which there is no schedule for

testing or certification, the licensee shall submit an application to

the NRC for authorized use of this equipment except as provided in this

part. The application must include evidence that the material and

performance characteristics of the equipment are capable of providing

the

[[Page 38519]]

proposed degree of protection under anticipated conditions of use. This

must be demonstrated either by licensee testing or on the basis of

reliable test information.

(c) The licensee shall implement and maintain a respiratory

protection program that includes:

(1) Air sampling sufficient to identify the potential hazard,

permit proper equipment selection, and estimate exposures;

(2) Surveys and bioassays, as necessary, to evaluate actual

intakes;

(3) Testing of respirators with APFs for operability (fit check for

face sealing devices and functional check for others) immediately prior

to each use;

(4) Written procedures regarding monitoring, including air sampling

and bioassays; training of respirator users; fit testing; respirator

selection; breathing air quality; inventory and control; storage,

issuance, maintenance, repair, testing, and quality assurance of

respiratory protection equipment; recordkeeping; and limitations on

periods of respirator use and relief from respirator use;

(5) Determination by a physician before the initial fitting of face

sealing respirators, before the first field use of non-face sealing

respirators, and either every 12 months thereafter, or periodically at

a frequency determined by a physician, that the individual user is

medically fit to use the respiratory protection equipment;

(6) Fit testing, with fit factor 10 times the APF for

negative pressure devices, and a fit factor 100 for any

positive pressure, continuous flow, and pressure-demand devices, before

the first field use of tight fitting, face-sealing respirators and

periodically thereafter at a frequency not to exceed 3 years.

(d) The licensee shall advise each respirator user that the user

may leave the area at any time for relief from respirator use in the

event of equipment malfunction, physical or psychological distress,

procedural or communication failure, significant deterioration of

operating conditions, or any other conditions that might require such

relief.

(e) The licensee shall use equipment, within limitations for type

and mode of use and shall make provision for vision correction,

adequate communication, low temperature work environments, and the

concurrent use of other safety or radiological protection equipment in

such a way as not to interfere with the proper operation of the

respirator.

(f) Standby rescue persons are required whenever one-piece

atmosphere-supplying suits, or any combination of supplied air

respiratory protection device and personnel protective equipment are

used, from which an unaided individual would have difficulty

extricating himself or herself. The standby persons must be equipped

with respiratory protection devices or other apparatus appropriate for

the potential hazards. The standby rescue persons, shall observe or

otherwise be in direct communication with the workers and must be

immediately available to assist them in case of a failure of the air

supply or for any other reason that requires relief from distress. A

sufficient number of standby rescue persons must be available to

effectively assist all users of this type of equipment.

(g) Whenever atmosphere-supplying respirators are used, they must

be supplied with respirable air of grade D quality or better as defined

by the Compressed Gas Association and endorsed by ANSI, in publication

G-7.1, ``Commodity Specification for Air,'' 1989, (ANSI-CGA G-7.1,

1989).

(h) No material or substance, the presence or absence of which is

under the control of the respirator wearer, may be present between the

skin of the wearer's face and the sealing surface of a tight-fitting

respirator facepiece.

(i) In estimating the exposure of individuals to airborne

radioactive materials, the concentration of radioactive material in the

air that is inhaled when respirators are worn is initially assumed to

be the ambient concentration in air without respiratory protection,

divided by the assigned protection factor. If the exposure is later

found to be greater than estimated, the corrected value must be used.

If the exposure is later found to be less than estimated, the corrected

value may be used.

6. Section 20.1704 is revised to read as follows:

Sec. 20.1704 Further restrictions on the use of respiratory protection

equipment.

The Commission may impose restrictions in addition to those in

Secs. 20.1702, 20.1703, and Appendix A to Part 20 in order to:

(a) Ensure that the respiratory protection program of the licensee

is adequate to limit exposures of individuals to airborne radioactive

materials consistent with maintaining total effective dose equivalent

ALARA; and

(b) Limit the extent to which a licensee may use respiratory

protection equipment instead of process or other engineering controls.

7. Section 20.1705 is added to read as follows:

Sec. 20.1705 Application for use of higher assigned protection

factors.

The licensee shall obtain authorization from the Commission before

using assigned protection factors in excess of those specified in

Appendix A to Part 20. The Commission may authorize a licensee to use

higher assigned protection factors on receipt of an application that--

(a) Describes the situation for which a need exists for higher

protection factors; and

(b) Demonstrates that the respiratory protection equipment provides

these higher protection factors under the proposed conditions of use.

8. Appendix A to Part 20 is revised to read as follows:

Appendix A to Part 20

Assigned Protection Factors for Respirators a

----------------------------------------------------------------------------------------------------------------

Assigned protection factors

------------------------------------------------------------------

Description Gases and

Modes b Particulate c vapors d

----------------------------------------------------------------------------------------------------------------

I. AIR PURIFYING RESPIRATORS:

Single-use disposable e.................. NP (e)

Facepiece, half mask f................... NP 10

Facepiece, full.......................... NP 100

Facepiece, half mask..................... PP 50

Facepiece, full.......................... PP 1000

Helmet/hood.............................. PP 1000

Facepiece, loose-fitting................. PP 25

II. ATMOSPHERE SUPPLYING RESPIRATORS:

[[Page 38520]]

1. Air-line respirator

Facepiece, half mask................. D 5 5

Facepiece, half mask................. CF 50 50

Facepiece, half mask................. PD 50 50

Facepiece, full...................... D 5 5

Facepiece, full...................... CF 1000 1,000

Facepiece, full...................... PD 1000 1,000

Helmet/hood.......................... CF 1000 1,000

Facepiece, loose-fitting............. CF 25 25

Suit................................. CF (g) (g)

2. Self-contained breathing

Apparatus (SCBA).....................

Facepiece, full...................... D h 50 h 50

Facepiece, full...................... PD i 10,000 i 10,000

Facepiece, full...................... RD h 50 h 50

Facepiece, full...................... RP i 10,000 i 10,000

III. COMBINATION RESPIRATORS:

Any combination of air-purifying and

atmosphere-supply respirators

(1) Assigned protection factor for type and

mode of operation as listed above

----------------------------------------------------------------------------------------------------------------

a. These assigned protection factors apply only in a respiratory protection program that meets the requirements

of this Part. They are applicable only to airborne radiological hazards and may not be appropriate to

circumstances when chemical or other respiratory hazards exist instead of, or in addition to, radioactive

hazards. Selection and use of respirators for such circumstances must also comply with Department of Labor

regulations contained in 29 CFR 1910.

Radioactive contaminants for which the concentration values in Table 1, Column 3 of Appendix B to Part 20 are

based on internal dose due to inhalation may, in addition, present external exposure hazards at higher

concentrations. Under these circumstances, limitations on occupancy may have to be governed by external dose

limits.

b. The mode symbols are defined as follows:

NP = negative pressure (air-purifying respirator)

PP = positive pressure (air-purifying respirator)

CF = continuous flow (supplied-air respirator)

D = demand (supplied-air respirator)

PD = pressure-demand (open circuit, supplied-air respirator)

RD = demand, recirculating (closed circuit SCBA)

RP = positive pressure, recirculating (closed circuit SCBA).

c. Air purifying respirators with APF 100 must be equipped with particulate filters that are at

least 99 percent efficient. Air purifying respirators with APF 100 must be equipped with

particulate filters that are at least 99.97 percent efficient.

d. Excluding radioactive contaminants that present an absorption or submersion hazard. For tritium oxide vapor,

approximately one-third of the intake occurs by absorption through the skin so that an overall protection

factor of 3 is appropriate when atmosphere-supplying respirators are used to protect against tritium oxide.

Exposure to radioactive noble gases is not considered a significant respiratory hazard, and protective actions

for these contaminants should be based on external (submersion) dose considerations. The licensee may apply to

the Commission for the use of an APF greater than 1 for sorbent cartridges as protection against airborne

radioactive gasses and vapors (e.g., radioiodine).

e. Licensees may permit individuals to use this type of respirator who have not been medically screened or fit

tested on the device provided that no credit be taken for their use in estimating intake or dose. It is also

recognized that it is difficult to perform an effective positive or negative pressure pre-use fit check on

this type of device. All other respiratory protection program requirements listed in Sec. 20.1703 apply. An

assigned protection factor has not been assigned for these devices. However, an APF equal to 10 may be used if

the licensee can demonstrate a fit factor of at least 100 by use of a validated or evaluated, qualitative or

quantitative fit test.

f. Under-chin type only. No distinction is made in this Appendix between elastomeric half-masks with replaceable

cartridges and those designed with the filter medium as an integral part of the facepiece (e.g., disposable or

reusable disposable). Both types are acceptable so long as the seal area of the latter contains some

substantial type of seal-enhancing material such as rubber or plastic, the two or more suspension straps are

adjustable, the filter medium is at least 99 percent efficient and all other requirements of this part are

met.

g. No NIOSH approval schedule is currently available for atmosphere supplying suits. This equipment may be used

in an acceptable respiratory protection program as long as all the other minimum program requirements, with

the exception of fit testing, are met [i.e., Sec. 20.1703].

h. The licensee should implement institutional controls to assure that these devices are not used in areas

immediately dangerous to life and health (IDLH).

i. This type of respirator may be used as an emergency device in unknown concentrations for protection against

inhalation hazards. External radiation hazards and other limitations to permitted exposure such as skin

absorption shall be taken into account in these circumstances. This device may not be used by any individual

who experiences perceptible outward leakage of breathing gas while wearing the device.

[[Page 38521]]

Dated at Rockville, Maryland this 13th day of July 1998.

For the Nuclear Regulatory Commission.

John C. Hoyle,

Secretary of the Commission.

[FR Doc. 98-19086 Filed 7-16-98; 8:45 am]

BILLING CODE 7590-01-P