Hazardous Air Pollutant List; Modification

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[AD-FRL-5520-5]

RIN 2060-AF33

Hazardous Air Pollutant List; Modification

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The EPA is amending the list of hazardous air pollutants in

Clean Air Act Section 112(b)(1) by removing the compound caprolactam

(CAS No. 105-60-2). This rulemaking was initiated in response to a

petition to delete the substance caprolactam which was filed by

AlliedSignal, Inc., BASF Corporation, and DSM Chemicals North

[[Page 30817]]

America under section 112(b)(3) of the Act. Based on the available

information concerning the potential hazards of and projected exposures

to caprolactam, EPA has made a determination pursuant to Clean Air Act

Section 112(b)(3)(C) that there are adequate data on the health and

environmental effects of caprolactam to determine that emissions,

ambient concentrations, bioaccumulation, or deposition of the compound

may not be reasonably anticipated to cause adverse human health or

environmental effects. Although EPA acknowledges that there are

scientific uncertainties in its analysis of the potential effects of

ambient caprolactam exposures, EPA does not regard any of these

uncertainties to be sufficiently material to preclude this

determination.

DATES: This final rule will be effective on June 18, 1996. Because this

final rule is based on a determination of nationwide scope and effect,

any petition for judicial review of this rule may be filed only in the

United States Court of Appeals for the District of Columbia and must be

filed no later than August 19, 1996.

ADDRESSES: The administrative record supporting this final rule is

collected in Docket Number A-94-33. All documents in that docket,

including a complete copy of the original petition, all comments on the

proposed rule, and a transcript of the public hearing, may be examined

between 8:00 A.M. and 4:30 P.M. on business days at the EPA Central

Docket Section, Waterside Mall, 401 M St., SW, Washington, D.C. 20460.

FOR FURTHER INFORMATION CONTACT: For specific information concerning

this final rule, contact Dr. Nancy B. Pate, Office of Air Quality

Planning and Standards (MD-12), U.S. EPA, Research Triangle Park, NC

27711, telephone (919) 541-5347.

SUPPLEMENTARY INFORMATION:

I. Introduction

A. The Delisting Process

Section 112 of the Clean Air Act contains a mandate for EPA to

evaluate and control emissions of hazardous air pollutants. Section

112(b)(1) includes an initial list of hazardous air pollutants that is

composed of specific chemical compounds and compound classes to be used

to identify source categories for which the EPA will subsequently

promulgate emissions standards.

Clean Air Act Section 112(b)(2) requires EPA to make periodic

revisions to the initial list of hazardous air pollutants set forth in

Section 112(b)(1) and outlines criteria to be applied in deciding

whether to add or delete particular substances. Section 112(b)(2)

identifies pollutants that should be listed as:

* * * pollutants which present, or may present, through inhalation

or other routes of exposure, a threat of adverse human health

effects (including, but not limited to, substances which are known

to be, or may reasonably be anticipated to be, carcinogenic,

mutagenic, teratogenic, neurotoxic, which cause reproductive

dysfunction, or which are acutely or chronically toxic) or adverse

environmental effects whether through ambient concentrations,

bioaccumulation, deposition, or otherwise * * *

To assist EPA in making judgments about whether a pollutant causes

an adverse environmental effect, Section 112(a)(7) defines an ``adverse

environmental effect'' as:

* * * any significant and widespread adverse effect, which may

reasonably be anticipated, to wildlife, aquatic life, or other

natural resources, including adverse impacts on populations of

endangered or threatened species or significant degradation of

environmental quality over broad areas.

Section 112(b)(3) establishes general requirements for petitioning

EPA to modify the hazardous air pollutant list by adding or deleting a

substance. Although the Administrator may add or delete a substance on

his own initiative, the burden is on a petitioner to include sufficient

information to support the requested addition or deletion under the

substantive criteria set forth in Sections 112(b)(3) (B) and (C). The

Administrator must either grant or deny a petition within 18 months of

receipt. If the Administrator decides to grant a petition, the Agency

publishes a written explanation of the Administrator's decision, along

with a proposed rule to add or delete the substance. If the

Administrator decides to deny the petition, the Agency publishes a

written explanation of the basis for denial. A decision to deny a

petition is final Agency action subject to review in the D.C. Circuit

Court of Appeals under Clean Air Act Section 307(b).

To promulgate a final rule deleting a substance from the hazardous

air pollutant list, Section 112(b)(3)(C) provides that the

Administrator must determine that:

* * * there is adequate data on the health and environmental effects

of the substance to determine that emissions, ambient

concentrations, bioaccumulation, or deposition of the substance may

not reasonably be anticipated to cause any adverse effects to the

human health or adverse environmental effects.

EPA will grant a petition to delete a substance, and publish a proposed

rule to delete that substance, if it makes an initial determination

that this criterion has been met. After affording an opportunity for

comment and for a hearing, EPA will make a final determination whether

the criterion has been met.

EPA does not interpret Section 112(b)(3)(C) to require absolute

certainty that a pollutant will not cause adverse effects on human

health or the environment before it may be deleted from the list. The

use of the terms ``adequate'' and ``reasonably'' indicate that the

Agency must weigh the potential uncertainties and their likely

significance. Uncertainties concerning the risk of adverse health or

environmental effects may be mitigated if EPA can determine that

projected exposures are sufficiently low to provide reasonable

assurance that such adverse effects will not occur. Similarly,

uncertainties concerning the magnitude of projected exposures may be

mitigated if EPA can determine that the levels which might cause

adverse health or environmental effects are sufficiently high to

provide reasonable assurance that exposures will not reach harmful

levels. However, the burden remains on a petitioner to resolve any

critical uncertainties associated with missing information. EPA will

not grant a petition to delete a substance if there are major

uncertainties which need to be addressed before EPA would have

sufficient information to make the requisite determination.

B. The Present Petition and Rulemaking

On July 19, 1993, EPA received a petition from AlliedSignal, Inc.,

BASF Corporation, and DSM Chemicals North America, Inc.

(``petitioners'') to delete caprolactam (CAS No. 105-60-2) from the

hazardous air pollutant list in Section 112(b)(1). Following receipt of

the petition, EPA conducted a preliminary evaluation to determine

whether the petition was complete according to Agency criteria. To be

deemed complete, a petition must consider all available health and

environmental effects data. A petition must also provide emissions data

sufficient to assess peak and average emissions for each source, and

must estimate the resultant exposures of people living in the vicinity

of the source. In addition, a petition must address the environmental

impacts associated with emissions to the ambient air and impacts

associated with the subsequent cross-media transport of those

emissions. EPA found the petition to delete caprolactam to be complete

and published a notice of receipt and request for comments in the

Federal

[[Page 30818]]

Register on August 26, 1993 (58 FR 45081).

After evaluating submissions received by EPA in response to the

notice of receipt, which included concerns expressed by citizens

concerning emissions of caprolactam by the AlliedSignal facility in

Irmo, South Carolina, EPA entered into discussions with AlliedSignal to

determine what could be done to address these concerns. On March 13,

1995, EPA executed two detailed emission reduction agreements with

AlliedSignal concerning the Irmo manufacturing facility and another

facility located in Chesterfield, Virginia, copies of which are

included in the public docket for this rulemaking. Under these

agreements, AlliedSignal is installing emission controls for

caprolactam which EPA believes are equivalent to the controls which

would have been required had EPA issued a standard to control these

sources under Section 112. The agreed emission controls will be

incorporated in federally enforceable operating permits for the

affected facilities, and will be in place years earlier than controls

would have otherwise been required. In addition, AlliedSignal has

established a citizen advisory panel concerning the Irmo facility,

which EPA is hopeful will improve communications with the community and

provide citizens an ongoing role in implementation of the agreed

emission reductions.

On September 8, 1995, based on a comprehensive review of the data

provided in the petition and otherwise provided to EPA, the Agency made

an initial determination that the statutory criterion for deletion of

caprolactam from the hazardous air pollutant list had been met. EPA

therefore granted the petition by AlliedSignal, Inc., BASF Corporation,

and DSM Chemicals and issued a proposed rule to delist caprolactam. (60

FR 48081, September 18, 1995).

EPA received a total of 19 comments on the September 18, 1995

proposed rule. EPA subsequently granted a request by a citizen's group

concerned about emissions from the AlliedSignal Irmo, SC facility to

extend the comment period until November 2, 1995. (60 FR 58589,

November 28, 1995). EPA conducted this delisting rulemaking pursuant to

the procedures established by Clean Air Act Section 307(d).

Accordingly, as provided by Section 307(d)(5), EPA held a public

hearing concerning the proposed rule in Irmo, SC on December 7, 1995. A

transcript of the hearing is included in the public docket for this

rulemaking. Pursuant to Section 307(d)(5), EPA kept the record of this

rulemaking open for thirty days after the December 7, 1995 hearing to

receive rebuttal and supplementary information.

II. Adverse Comments and EPA Responses

A. Overview

Of the 19 written comments which were received concerning the

proposed delisting of caprolactam, seven commenters supported and seven

commenters opposed delisting. Other commenters expressed concerns

regarding particular elements of the Agency's assessment, but did not

expressly support or oppose the proposal. Many of the persons who made

statements at the public hearing held on December 7, 1995 in Irmo, SC

expressed opposition to the proposed delisting, in most cases because

of a belief that emissions by AlliedSignal's Irmo facility were the

cause of adverse health effects in their homes or community. Many of

the commenters opposing the delisting of caprolactam were members or

representatives of People United for a Responsible Environment (PURE),

a citizen's group located in the Irmo-St. Andrews area of Columbia, SC.

EPA has considered carefully all of the comments both supporting

and opposing the proposed delisting, focussing in particular on those

comments which suggested potential deficiencies in the substantive

rationale upon which EPA based its initial determination that the

criterion in Clean Air Act Section 112(b)(3)(C) had been met. A summary

of the comments and the EPA responses to them has been included in the

docket for this proceeding. In this notice, EPA will discuss adverse

comments which it received and its response to them.

B. Toxicity Data

Opponents of delisting commented that EPA should place greater

emphasis on the findings in several Eastern European studies, which

reported adverse reproductive effects in animals and exposed workers

following inhalation of caprolactam. Unfortunately, there are numerous

methodologic problems with the manner in which the cited studies were

performed and documented which severely limit their value for risk

assessment. Well-designed, documented and conducted animal studies do

indicate that the most sensitive chronic health effect endpoint

associated with caprolactam exposure is reduced mean fetal body weight

(noted in a rodent reproductive study). However, since the reported

results in these Eastern European studies cannot be readily reconciled

with subsequent studies, EPA does not believe that these studies

warrant any change in its risk assessment for caprolactam.

Opponents of delisting also have argued that the available animal

data on inhalation of caprolactam is inadequate to support the Agency's

conclusions, and that EPA should wait for the results from the

subchronic rat inhalation study of caprolactam which AlliedSignal is

currently performing before taking final action in this rulemaking. EPA

agrees that the available animal data on inhalation of caprolactam is

very limited in comparison to the large number of studies of

caprolactam ingestion. This is largely because the physical properties

of the substance make it difficult to generate stable atmospheres of

caprolactam at levels which would be toxicologically significant and to

control for possible secondary exposure to caprolactam by the oral

route. However, EPA believes that the commenters who assert that EPA

should wait to take action until after the current subchronic

inhalation study has been completed misunderstand the study's purpose

and likely significance.

Based on the currently available human and animal data, the most

sensitive effect of inhalation exposure to caprolactam is irritation of

the eye, nose, and throat. In a limited but reliable occupational study

of workers exposed to airborne caprolactam over nearly two decades,

irritant effects in the nose and throat were observed in some workers

at all levels above 46 mg/m3, and no distress was noted among

workers at concentrations ranging up to 32 mg/m3. This approximate

no observed effect level of 32 mg/m3 for acute irritation by

caprolactam in humans is consistent with one animal study, in which

brief exposure to caprolactam levels up to 26 mg/m3 did not elicit

any of the physiologic responses typical of irritants.

EPA believes that projected exposures of the general population to

a substance in the ambient air at concentrations which result in acute

irritation can be an appropriate basis for inclusion of that substance

on the list of hazardous air pollutants. However, in the case of

caprolactam, the highest modeled one-hour caprolactam concentration

near any facility based on reported emissions was approximately 1 mg/

m3, well below the lowest documented irritation level of 46 mg/

m3.

The target exposure levels in the subchronic inhalation study being

conducted by AlliedSignal are 25, 75,

[[Page 30819]]

and 250 mg/m3. The new inhalation study will provide additional

information on potential adverse effects on the respiratory tract, as

well as any adverse systemic effects, associated with sustained

inhalation of caprolactam. Although EPA is reluctant to make

quantitative comparisons between the oral and inhalation routes, EPA

has previously calculated that the oral NOAEL (No Observed Adverse

Effect Level) for reproductive effects of 50 mg/kg/day would be

approximately equivalent to 175 mg/m3, after adjusting for a human

body weight of 70 kg, 100 percent absorption, and a human inhalation

rate of 20 m3/day. EPA considers it probable that the new

inhalation study will permit better quantification of the dose-response

relationship for potential portal of entry effects, but it is less

clear whether even the highest concentration achieved by the new study

will be sufficient to cause any of the systemic effects observed in

previous oral studies.

The purpose of the new inhalation study is to enable a more precise

quantitative dose response assessment for the inhalation effects of

caprolactam exposure. While the study may be quite useful in this

respect, EPA considers it unlikely that the study will change the more

general conclusions of the risk assessment on which this final rule is

based. In other words, EPA does not consider the uncertainties the new

study is designed to address to be material to the overall risk

determination underlying today's action.

Even if the new study were to detect portal of entry effects in

rats following repeated exposure at the lowest target concentration of

25 mg/m3, this would probably have greater significance in an

occupational context than in assessing the risks associated with

ambient exposures. The new study will expose animals to this

concentration for 13 weeks. The maximum modeled ambient caprolactam

concentration for a 24-hour period is 0.25 mg/m3, two orders of

magnitude below the lowest target concentration in the new study. (The

maximum modeled ambient concentration on an annual basis is 0.05 mg/

m3.)

Given the animal and human data already available, EPA considers it

quite improbable that the new study will detect adverse systemic

effects at the lower exposure levels. However, in the event that such

effects are observed, EPA will review today's action in light of such

data.

EPA wishes to stress that its decision that there is no need to

wait for submission of the new inhalation study is based on the

Agency's conclusion that the present data are already adequate to

support the requisite statutory determination. EPA does not agree with

the argument made by AlliedSignal in its comments that previous EPA

delisting actions under Section 313 of the Emergency Planning and

Community Right-to-Know Act (EPCRA) provide precedent that would enable

EPA to proceed with delisting under Clean Air Act Section 112 when

research which is clearly material to its risk assessment is still

underway. Unlike Clean Air Act Section 112(b)(3)(C), which requires EPA

to determine that currently available data are adequate to support a

determination that a substance may not reasonably be expected to cause

adverse effects, EPCRA Section 313(d)(3) provides that a chemical may

be deleted if there is not sufficient evidence to establish that it

causes certain adverse effects.

C. Human Effects Information

In comments submitted by PURE and statements by individual citizens

at the public hearing, many commenters asserted their belief that there

is a relation between various adverse human health effects and

caprolactam emissions by the AlliedSignal Irmo facility. The effects

described include headaches, allergies, sinus problems, respiratory

disorders, multiple chemical sensitivity, chronic fatigue syndrome,

various digestive disorders, neurologic disorders, and several types of

cancer. Although reports of irritation of the upper respiratory tract

are qualitatively similar to the effects observed at far higher

concentrations in occupational studies, EPA is not aware of any

evidence which would indicate a relation between the occurrence of

these common disorders in the general population and caprolactam

exposure. EPA is also unaware of any evidence which would support the

claimed relationship between caprolactam exposure and the other

specific diseases which were mentioned. In the absence of any reliable

epidemiologic or clinical information, or any other collateral evidence

which would suggest the biological plausibility of the described

effects, EPA cannot justify affording any weight to such anecdotal

evidence in its risk assessment.

The purported relationship between caprolactam exposure and the

symptoms of multiple chemical sensitivity (MCS) requires separate

discussion. There is at present no medical consensus concerning the

definition or the nature of this disorder. EPA is aware that some

individuals and their physicians report they are unusually sensitive to

multiple chemicals to which the general population is commonly exposed

without ill effect. One person who spoke at the public hearing asserted

that she is so sensitive to chemicals that she cannot use a dishwashing

machine in her home. While EPA recognizes the formidable challenges and

problems which may be faced by such individuals as they attempt to

function in modern industrial society, such unusual and extreme

sensitivity is not among the effects that EPA was directed to consider

in identifying and listing hazardous air pollutants.

EPA is aware that a number of individuals in the Irmo-St. Andrews

area have firmly concluded that caprolactam is the cause of health

problems which they or their families have experienced. EPA accepts the

concern and personal sincerity of these individuals' beliefs, but is

not aware of any scientific evidence which would support them. EPA

acknowledges the disappointment its decision to delist will cause these

individuals, but respectfully suggests that the substantive changes at

the Irmo facility have more practical significance to them than the

plausibility of the claimed effects. EPA has taken steps which assure

that there will be Federally enforceable reductions of caprolactam

emissions at the Irmo facility equivalent to those which would have

been required had caprolactam remained on the list of hazardous air

pollutants, and that such reductions will be in place years before they

would otherwise have been required.

The Agency for Toxic Substances and Disease Registry (ATSDR)

commented on the EPA discussion of an ATSDR report in the proposed

rule. ATSDR noted that EPA had called the report a ``preliminary

screening study,'' although the ATSDR reviewed only the available

literature, environmental monitoring data, and written and verbal

reports of health concerns from individuals, and no health screening

was performed on individuals. ATSDR also noted that the proposed rule

had misquoted the ATSDR report, and that its conclusions concerning the

Irmo Facility should not be generalized or applied to other facilities.

The use by EPA of the term ``preliminary screening study'' was not

intended to imply that any health screening had been performed by

ATSDR, and EPA regrets any confusion this phrase may have caused. In

its report, ATSDR did reach conclusions regarding the Irmo facility

which are consistent with the EPA analysis, but the determination by

EPA that the

[[Page 30820]]

statutory criterion for delisting has been met is not predicated on the

ATSDR conclusions. As far as the quotation from the ATSDR report in the

proposed rule, the omission of several words was inadvertent. The

correct quotation is:

``* * * the concentration of hazardous substances found in

ambient air sampling were not of health concern and the community

health concerns were not plausibly related to the release of

hazardous substances.'' (correction italicized)

Finally, although the determination by EPA that caprolactam meets

the statutory criterion for delisting is generic in nature, EPA never

intended to generalize the ATSDR findings to other facilities or the

communities in which they are located.

One frequent comment by the residents in the Irmo-St. Andrews area

was that EPA should study the residents of that area before proceeding

to delist caprolactam. EPA has carefully evaluated the feasibility and

scientific value of an epidemiologic study and has determined that it

would neither be practical or informative. In its evaluation, EPA

utilized five criteria for determining the feasibility of community

environmental studies suggested by Bender, et al., in a 1990 article in

the American Journal of Epidemiology. A memorandum summarizing this EPA

evaluation has been included in the docket.

The EPA evaluation makes it clear that a meaningful study of

persons exposed to caprolactam emissions from the Irmo facility cannot

be conducted. Key problems with such a study include the selection of

biologically plausible health effects in the exposed population, the

identification and measurement of other factors which might contribute

to these health effects, and the lack of adequate statistical power to

detect differences between exposed and unexposed populations.

As noted above, it is difficult to identify the specific health

effects which would be the focus of such a study. If there were an

unusual cluster of a single rare disease in the community, a credible

allegation of a potential relation between that disease and caprolactam

exposure, and all persons with that disease from an identified

population including exposed individuals could be examined, a case-

control study might be practicable. However, none of these factors are

present here.

A cohort study of an exposed population (such as students at a

nearby elementary school) would also be impractical. The non-specific

complaints in the upper respiratory tract which are most frequently

asserted by residents to be potentially related to caprolactam exposure

have a very high incidence in any population. Such upper respiratory

complaints can be caused by other pollutants, allergens, and infectious

agents, and it would be difficult if not impossible to adequately

control for these confounding factors in the study and control

populations. Finally, the size of any potentially exposed valid study

population that could be identified would probably not be large enough

to provide sufficient statistical power to detect significant

differences even if they do exist.

EPA realizes that there is a perception by many concerned citizens

that any hypothetical relation between actual exposures and actual

health effects can be scientifically studied. Unfortunately, this is

not the case. Given the currently available information and the

analytic tools provided by current science, EPA sees little or no

utility to an epidemiologic study of caprolactam exposure in the Irmo-

St. Andrews area. This is similar to the conclusion reached by ATSDR in

its report.

D. Exposure Information

One commenter stated that the exposure estimates by the petitioners

and by EPA were incomplete because they did not consider caprolactam

emissions from hot mix asphalt (HMA) plants. The commenter estimated

that caprolactam emissions from individual HMA plants could exceed the

major source threshold of 10 tons per year, and that total caprolactam

emissions from such facilities could be as high as 18,000 tons per

year. Caprolactam is an ingredient in liquid anti-stripping agents

containing bis(hexamethylene)triamine (BHMT), which are used in some

HMA plants.

Prior to submission of this comment, EPA was unaware of HMA plants

as a potential source of caprolactam emissions. If the commenter's

estimates of emissions from HMA plants were determined to be correct,

it was clear that the failure of the petitioners to address such

emissions in their petition had been a significant omission.

AlliedSignal investigated emissions of caprolactam from HMA plants

and submitted comments summarizing its findings. Although the commenter

had estimated based on a material safety data sheet for one anti-

stripping agent that caprolactam levels in such products are 5%, the

actual level of caprolactam found in this product by AlliedSignal was

.38%. In nine such products tested by AlliedSignal, the average

caprolactam level was .79%, and the highest level found was 1.8%. Based

on other assumptions suggested by the original commenter, AlliedSignal

estimated that worst-case emissions from an HMA plant using a liquid

anti-stripping agent containing the maximum caprolactam level of 1.8%

would be 3.6 tons per year. AlliedSignal noted that not all HMA plants

use liquid anti-stripping agents, and not all such agents contain BHMT

(and thus caprolactam). Based on estimates of the total quantity of

liquid anti-stripping agents produced annually, and the percentage of

such agents containing BHMT, AlliedSignal concluded that no more than

27 tons/year of caprolactam is emitted from all HMA plants.

EPA considers the estimates by AlliedSignal of caprolactam

emissions by HMA plants to be reasonable based on the information

provided. Based on these estimates, no single HMA plant would

constitute a major source of caprolactam. Because the estimated

emissions from plants in the HMA source category are lower than

reported emissions from the other source categories evaluated in the

original petition, EPA does not believe that emissions from such

sources would affect its conclusion that the statutory criterion for

delisting has been met.

Several commenters expressed doubt as to the reliability of the

exposure modeling on which the caprolactam delisting petition and the

EPA risk assessment are based. In general, EPA believes that the

exposure models utilized by the petitioners produce conservative

results. Although actual ambient monitoring data around facilities

emitting caprolactam is very limited, AlliedSignal submitted

information indicating that actual measurements of ambient caprolactam

levels at a monitoring station near its Irmo facility operated by the

State of South Carolina Department of Health and Environmental Control

were generally less than the concentrations for that location which

were predicted by modeling.

Several commenters expressed concern that the EPA conclusions

regarding the adverse effects of current caprolactam emissions do not

assure that new sources with greater caprolactam emissions than those

identified in the petition will not emerge in the future. A related

concern was that the agreements with AlliedSignal regarding control of

caprolactam emissions at its manufacturing facilities will not affect

emissions at future facilities.

EPA does not interpret Section 112(b)(3)(C) to require

consideration of hypothetical emissions from facilities that might be

constructed in the future.

[[Page 30821]]

The logical consequence of such an expansive construction would be that

no substance could ever be delisted, due to the hypothetical

possibility of some future facility with emissions large enough to

cause adverse effects. In the event that some future facility has

uncontrolled caprolactam emissions great enough to change the

conclusions of the present EPA risk assessment, EPA can revisit its

decision to delist caprolactam at that time.

EPA readily acknowledges that the agreements with AlliedSignal do

not apply to other caprolactam emitting facilities, either those

presently in existence or those which might be constructed in the

future. Although EPA has been unable to establish any link between

caprolactam emissions at the Irmo facility and health effects in that

community, EPA negotiated an agreement with AlliedSignal concerning

installation of additional emission controls in order to alleviate the

stated concerns of the residents in that community. EPA also reached

agreement with AlliedSignal concerning control of emissions at its

Chesterfield, VA manufacturing facility because that facility had large

uncontrolled caprolactam emissions analogous to those at the Irmo

facility. While EPA does not consider the Federally enforceable

reductions in caprolactam emissions at either of these facilities to be

essential to meet the statutory criteria for delisting, these

reductions do provide substantial additional assurance that adverse

human health effects will not occur. Moreover, the agreed reductions

will be in place well before any mandatory emission reductions which

would have resulted from the continued listing of caprolactam as a

hazardous air pollutant.

E. Emission Reductions by AlliedSignal

Several commenters from the Irmo-St. Andrews area expressed doubt

concerning the enforceability of the caprolactam reductions at the Irmo

facility which have been agreed to by AlliedSignal. Such comments are

simply erroneous. AlliedSignal has unequivocally agreed that the key

terms and conditions which assure such reductions will be incorporated

into the Federally enforceable Title V operating permit for the Irmo

facility. This is the same permit which would have been utilized to

enforce any emission standard controlling caprolactam emissions from

this facility adopted pursuant to Clean Air Act Section 112.

In its comments, PURE argued that EPA should not presume that the

emission reductions to be achieved by AlliedSignal at the Irmo facility

are equivalent to the reductions which would be required by a Maximum

Achievable Control Technology (MACT) standard issued under Section 112,

because EPA has not gone through the steps which would be necessary to

determine what MACT would be. Since any MACT standard issued for the

source category including the AlliedSignal Irmo facility would not be

issued until years from now, EPA cannot say with precision what such a

standard would ultimately require. However, EPA has determined that the

emissions control technology being installed at the AlliedSignal Irmo

and Chesterfield facilities is likely to perform at least as well as

that which has been demonstrated at other well-controlled facilities.

EPA bases its conclusions concerning the effectiveness of emission

controls being installed at the AlliedSignal facilities on the emission

and production information contained in the petition and produced by

the petitioners during the rulemaking, and on visits by EPA to several

operating Nylon 6 production facilities, including the AlliedSignal

Irmo facility and the BASF Clemson facility. (PURE representatives have

cited BASF as a company which does a good job of controlling its

caprolactam emissions.) EPA has evaluated each of six Nylon 6

production facilities to determine the ratio of the amount of

caprolactam emitted to the amount of Nylon 6 fiber production. The

ratio of emissions to production at the AlliedSignal Irmo and

Chesterfield facilities after all required controls have been installed

will be less than the present ratio of emissions to production at all

other facilities except the BASF Anderson plant, which has lower

emissions because it spins Nylon 6 fiber but receives polymerized

caprolactam from another site. Although the analysis underlying a MACT

standard would be more detailed, and would likely involve separate

analysis of caprolactam emissions for polymerization, depolymerization,

and spinning operations, EPA considers it improbable that a MACT

standard based on presently demonstrated technologies would require

greater control of caprolactam emissions at the AlliedSignal facilities

than is required by the agreements AlliedSignal has executed.

Several commenters complained that the agreement between EPA and

AlliedSignal does not adequately regulate emergency releases from the

plant. Under general MACT provisions, releases during periods of upset

and abnormal operation are not considered in determining compliance

with MACT standards. Thus, the implicit assumption that a MACT standard

would regulate emergency releases more stringently than the agreement

is mistaken. In addition, the commenters appear to overestimate the

significance of such releases. Figures provided by AlliedSignal

indicate that additional caprolactam emissions associated with

scheduled maintenance and unscheduled malfunctions of emission control

equipment at the Irmo facility represent less than one percent of the

total caprolactam emissions by that facility.

The agreement concerning the AlliedSignal Irmo facility does

contain provisions which require expeditious reporting of any emission

control equipment upset or malfunction, as well as any emergency

releases, to the South Carolina Department of Health and Environmental

Control. The agreement also requires prompt repair of any

malfunctioning emission control equipment, and installation of pressure

control devices on those emission points most susceptible to emergency

releases.

F. Delisting Criteria

In its comments, PURE asserted that EPA is required to consider

occupational exposures in deciding whether to delist caprolactam. EPA

firmly disagrees with this comment. The language of Section

112(b)(3)(C) refers to ``emissions, ambient concentrations,

bioaccumulation, or deposition of the substance.'' Nothing in this

language suggests that EPA should consider worker exposures in its

delisting assessment. Moreover, it would be illogical to assume that

worker exposures should be considered in deciding whether to delist

when continued listing would not itself lead to any requirement that

occupational exposures be controlled.

In its comments, PURE also argued that the proposed delisting would

be unlawful because it assumes future compliance by AlliedSignal with

the agreed emission reductions, thereby circumventing the purposes of

the Clean Air Act. It could be argued that consideration of future

emission reductions in a decision to delist a substance from the list

of hazardous air pollutants is a reasonable construction of Section

112(b)(3)(C) consistent with the purposes of the Clean Air Act, so long

as such reductions will be as enforceable as those which might be

required by a MACT standard and will be in place before any MACT

standard could be issued. However, in this instance it was not

necessary to resolve this question. EPA has determined that

[[Page 30822]]

the petitioners have satisfied the statutory criterion for delisting in

Section 112(b)(3)(C) based on the emissions reported in the delisting

petition. The agreements by AlliedSignal requiring enforceable

reductions in caprolactam emissions at its facilities provide

additional assurance that the agency's determination is correct, but

are not an essential element in the risk assessment on which that

determination is based.

III. Final Rule

A. Rationale for Action

The detailed factual rationale supporting the Agency's initial

determination that the criterion in Clean Air Act Section 112(b)(3)(C)

had been met is set forth in the proposed rule published in the Federal

Register on September 18, 1995 (60 FR 48081). As is apparent from the

discussion above, although EPA has done substantial additional analysis

pursuant to the comments submitted during the subsequent rulemaking,

none of those comments have caused EPA to revise the basic scientific

analysis on which that initial determination was predicated. EPA hereby

incorporates in its rationale for this final rule the substantive

assessment of potential hazards, projected exposures, human risk, and

environmental effects set forth in the proposed rule to delist

caprolactam. Based on that assessment, the Agency's evaluation of the

comments and additional information submitted during the rulemaking (as

summarized above), and on the other materials which have been

incorporated in the public docket for this rulemaking, EPA has made a

determination that there is adequate data on the health and

environmental effects of caprolactam to determine that emissions,

ambient concentrations, bioaccumulation or deposition of caprolactam

may not reasonably be anticipated to cause any adverse effects to human

health or adverse environmental effects. On that basis, caprolactam is

hereby deleted from the list of hazardous air pollutants set forth in

Clean Air Act Section 112(b)(1). This deletion shall be final on the

effective date of this rule.

B. Implementation

Although EPA intends in the future to conduct a rulemaking to

codify the hazardous air pollutant list set forth in Clean Air Act

Section 112(b)(1) and to correct various technical errors in the

statutory list which have been identified since 1990, the list is at

present uncodified. Therefore, today's rule does not revise the text of

any existing provision of the Code of Federal Regulations. However, on

the effective date of this rule, caprolactam will be deleted for all

purposes from the list set forth in Section 112(b)(1). To avoid

confusion concerning the status of caprolactam, pending the rulemaking

which will codify and correct the list set forth in Section 112(b)(1),

EPA will add to the Code of Federal Regulations a brief provision

confirming that caprolactam has been deleted from the list.

EPA included in the proposed rule to delist caprolactam a provision

providing immediate relief, on an interim basis, for certain facilities

which might otherwise have been required to apply for Title V operating

permits based solely on the continued inclusion of caprolactam on the

list of hazardous air pollutants. That provision suspended the listing

of caprolactam, for the duration of this rulemaking, solely for the

limited purpose of determining the applicability of Title V permitting

requirements. The interim relief provided in the proposed rule is no

longer necessary and will expire by its own terms on the effective date

of this final rule.

C. Effective Date

This final rule will be effective on June 18, 1996, the date it is

published in the Federal Register. Although Section 553(d) of the

Administrative Procedure Act, 5 U.S.C. 553(d), provides that

substantive rules must be published at least 30 days prior to their

effective date, this requirement does not apply to this rule. First,

this rule was promulgated pursuant to Clean Air Act Section 307(d), and

that provision expressly states that the provisions of Section 553 do

not apply to this action. Second, even under Section 553, the

requirement that a rule be published 30 days prior to its effective

date does not apply to a rule

``which grants or recognizes an exemption or relieves a

restriction.''

D. Judicial Review

This final rule deleting caprolactam from the list of hazardous air

pollutants in Clean Air Act Section 112(b)(1) is based on a

determination of nationwide scope and effect. A petition for judicial

review of this final rule may be filed solely in the United States

Court of Appeals for the District of Columbia. Any such petition for

judicial review of this rule must be filed no later than August 19,

1996. In any resulting action, no objection can be made which was not

raised with reasonable specificity during the period for public comment

(including the public hearing).

IV. Miscellaneous

A. Executive Order 12866

Under Executive Order 12866 (58 FR 57735, October 4, 1993), EPA

must determine whether this rule is ``significant'' and therefore

subject to review by the Office of Management and Budget under the

Executive Order. The Order defines ``significant regulatory action'' as

one that is likely to result in a rule that may:

1. Have an annual effect on the economy of $100 million or more or

adversely affect in a material way the economy, a sector of the

economy, productivity, competition, jobs, the environment, public

health or safety, or State, local or tribal governments or communities;

2. Create a serious inconsistency or otherwise interfere with an

action taken or planned by another agency;

3. Materially alter the budgetary impact of entitlement, grants,

user fees, or loan programs or the rights and obligations of recipients

thereof; or

4. Raise novel legal or policy issues arising out of legal

mandates, the President's priorities, or the principles set forth in

the Executive Order.

This action will not result in an annual effect on the economy of

$100 million or another adverse economic impact, does not create a

serious inconsistency or interfere with another agency's action, and

does not materially alter the budgetary impacts of entitlement, grants,

user fees, etc. While States may lose Title 5 permit fees as a direct

result of this rule, the number of affected facilities is not believed

to be significant. However, since this action is the Agency's first

decision to modify the hazardous air pollutant list, EPA believes that

it could be construed as raising novel legal or policy issues and has

therefore submitted this rule for OMB review under Executive Order

12866.

B. Regulatory Flexibility Analysis

EPA has determined that it is not necessary to prepare a regulatory

flexibility analysis in connection with this final rule. This rule will

reduce regulatory burdens on small businesses which would otherwise be

associated with retention of caprolactam on the list of hazardous air

pollutants. EPA has determined that this rule will have no adverse

effect on small businesses. Accordingly, this rule will not have ``a

significant impact on a substantial number of small entities,'' as that

phrase is utilized in Section 605(b) of the Regulatory Flexibility Act,

as amended.

[[Page 30823]]

C. Unfunded Mandates

Under Section 202 of the Unfunded Mandates Reform Act of 1995, EPA

must prepare a written statement to accompany any rules that have

``Federal mandates'' that may result in the expenditure by the private

sector of $100 million or more in any one year. Under Section 205, EPA

must select the most cost-effective and least burdensome alternative

that achieves the objective of such a rule and that is consistent with

statutory requirements. Section 203 requires EPA to establish a plan

for informing and advising small governments that may be significantly

and uniquely affected by the rule.

The Unfunded Mandates Act defines a ``Federal private sector

mandate'' for regulatory purposes as one that, among other things,

``would impose an enforceable duty upon the private sector.'' This

final rule to modify the hazardous air pollutant list to delete

caprolactam is deregulatory in nature and does not impose any

enforceable duties upon the private sector. Therefore, this rulemaking

is not a ``Federal private sector mandat'' and is not subject to the

requirements of Section 202 or Section 205 of the Unfunded Mandates

Act. As to Section 203, EPA finds that small governments will not be

significantly and uniquely affected by this rulemaking.

D. Submission to Congress and the General Accounting Office

Under section 801(a)(1)(A) of the Administrative Procedures Act

(APA) as amended by the Small Business Regulatory Enforcement Fairness

Act of 1996, EPA submitted a report containing this rule and other

required information to the U.S. Senate, the U.S. House of

Representatives and the Comptroller General of the General Accounting

Office prior to publication of the rule in today's Federal Register.

This rule is not a ``major rule'' as defined by section 804(2) of the

APA as amended.

List of Subjects in 40 CFR Part 63

Environmental protection, Air pollution control, Hazardous

substances.

Dated: June 7, 1996.

Carol M. Browner,

Administrator.

40 CFR part 63 is amended as follows:

PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS

FOR SOURCE CATEGORIES

1. The authority citation for part 63 continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart C--[Amended]

2. Subpart C is amended by adding Sec. 63.60 and adding and

reserving Secs. 63.61 through 63.69 to read as follows:

Sec. 63.60 Deletion of caprolactam from the list of hazardous air

pollutants.

The substance caprolactam (CAS number 105602) is deleted from the

list of hazardous air pollutants established by 42 U.S.C. 7412(b)(1).

Secs. 63.61-63.69 [Reserved]

[FR Doc. 96-15445 Filed 6-17-96; 8:45 am]

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