[Federal Register Volume 61, Number 118 (Tuesday, June 18, 1996)]
[Rules and Regulations]
[Pages 30816-30823]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-15445]



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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/m<SUP>3, and no distress was noted among 
workers at concentrations ranging up to 32 mg/m<SUP>3. This approximate 
no observed effect level of 32 mg/m<SUP>3 for acute irritation by 
caprolactam in humans is consistent with one animal study, in which 
brief exposure to caprolactam levels up to 26 mg/m<SUP>3 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/
m<SUP>3, well below the lowest documented irritation level of 46 mg/
m<SUP>3.
    The target exposure levels in the subchronic inhalation study being 
conducted by AlliedSignal are 25, 75,

[[Page 30819]]

and 250 mg/m<SUP>3. 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/m<SUP>3, after adjusting for a human 
body weight of 70 kg, 100 percent absorption, and a human inhalation 
rate of 20 m<SUP>3/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/m<SUP>3, 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/m<SUP>3, 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/
m<SUP>3.)
    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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