[Federal Register Volume 82, Number 12 (Thursday, January 19, 2017)]
[Proposed Rules]
[Pages 7432-7461]
[FR Doc No: 2017-01229]

Vol. 82

Thursday,

No. 12

January 19, 2017

Part XIV

Environmental Protection Agency

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40 CFR Part 751

Trichloroethylene (TCE); Regulation of Use in Vapor Degreasing Under
TSCA Section 6(a); Proposed Rule

Federal Register / Vol. 82 , No. 12 / Thursday, January 19, 2017 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 751

[EPA-HQ-OPPT-2016-0387; FRL-9950-08]
RIN 2070-AK11

Trichloroethylene (TCE); Regulation of Use in Vapor Degreasing
Under TSCA Section 6(a)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: Trichloroethylene (TCE) is a volatile organic compound widely
used in industrial and commercial processes and has some limited uses
in consumer and commercial products. EPA identified significant health
risks associated with TCE use in vapor degreasing and EPA's proposed
determination is that these risks are unreasonable risks. To address
these unreasonable risks, EPA is proposing under section 6 of the Toxic
Substances Control Act (TSCA) to prohibit the manufacture (including
import), processing, and distribution in commerce of TCE for use in
vapor degreasing; to prohibit commercial use of TCE in vapor
degreasing; to require manufacturers, processors, and distributors,
except for retailers of TCE for any use, to provide downstream
notification of these prohibitions throughout the supply chain; and to
require limited recordkeeping.

DATES: Comments must be received on or before March 20, 2017.

ADDRESSES: Submit your comments, identified by docket identification
(ID) number EPA-HQ-OPPT-2016-0387, at http://www.regulations.gov.
Follow the online instructions for submitting comments. Once submitted,
comments cannot be edited or withdrawn. EPA may publish any comment
received to its public docket. Do not submit electronically any
information you consider to be Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered the official comment
and should include discussion of all points you wish to make. EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e., on the Web, cloud, or other file sharing
system). For additional submission methods (e.g., mail or hand
delivery), the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
    Docket. Docket ID No. EPA-HQ-OPPT-2016-0387 contains supporting
information used in developing the proposed rule, comments on the
proposed rule, and additional supporting information. In addition to
being available online at http://www.regulations.gov, the docket is
available for inspection and copying between 8:30 a.m. and 4:30 p.m.,
Monday through Friday, excluding federal holidays, at the U.S.
Environmental Protection Agency, EPA Docket Center Reading Room, WJC
West Building, Room 3334, 1301 Constitution Avenue NW., Washington, DC
20004. A reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT: For technical information contact:
Cindy Wheeler, Chemical Control Division (7405M), Office of Pollution
Prevention and Toxics, Environmental Protection Agency, 1200
Pennsylvania Ave. NW., Washington, DC 20460-0001; telephone number:
(202) 566-0484; email address<EMAIL_ADDRESS>    For general information contact: The TSCA-Hotline, ABVI-Goodwill,
422 South Clinton Ave., Rochester, NY 14620; telephone number: (202)
554-1404; email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. Executive Summary

A. Does this action apply to me?

    You may be potentially affected by this proposed action if you
manufacture (defined under TSCA to include import), process, or
distribute in commerce TCE or commercially use TCE in vapor degreasers.
The following list of North American Industrial Classification System
(NAICS) codes is not intended to be exhaustive, but rather provides a
guide to help readers determine whether this document applies to them.
Potentially affected entities may include:
     Petroleum Refineries (NAICS code 324110).
     Petroleum Lubricating Oil and Grease Manufacturing (NAICS
code 324191).
     Petrochemical Manufacturing (NAICS code 325110).
     Industrial Gas Manufacturing (NAICS code 325120).
     Other Basic Inorganic Chemical Manufacturing (NAICS code
325180).
     All Other Basic Organic Chemical Manufacturing (NAICS code
325199).
     Plastics Material and Resin Manufacturing (NAICS code
325211).
     Synthetic Rubber Manufacturing (NAICS code 325212).
     Paint and Coating Manufacturing (NAICS code 325510).
     Adhesive Manufacturing (NAICS code 325520).
     Soap and Other Detergent Manufacturing (NAICS code
325611).
     Polish and Other Sanitation Good Manufacturing (NAICS code
325612).
     All Other Miscellaneous Chemical Product and Preparation
Manufacturing (NAICS code 325998).
     Unlaminated Plastics Film and Sheet (except Packaging)
Manufacturing (NAICS code 326113).
     All Other Plastics Product Manufacturing (NAICS code
326199).
     Rubber and Plastics Hoses and Belting Manufacturing (NAICS
code 326220).
     All Other Rubber Product Manufacturing (NAICS code
326299).
     Cement Manufacturing (NAICS code 327310).
     Ground or Treated Mineral and Earth Manufacturing (NAICS
code 327992).
     Iron and Steel Pipe and Tube Manufacturing from Purchased
Steel (NAICS code 331210).
     Steel Wire Drawing (NAICS code 331222).
     Copper Rolling, Drawing, Extruding, and Alloying (NAICS
code 331420)
     Nonferrous Metal (except Copper and Aluminum) Rolling,
Drawing, and Extruding (NAICS code 331491).
     Nonferrous Metal Die-Casting Foundries (NAICS code
331523).
     Powder Metallurgy Part Manufacturing (NAICS code 332117).
     Metal Crown, Closure, and Other Metal Stamping (except
Automotive) (NAICS code 332119).
     Saw Blade and Hand Tool Manufacturing (NAICS code 332216).
     Metal Window and Door Manufacturing (NAICS code 332321).
     Power Boiler and Heat Exchanger Manufacturing (NAICS code
332410).
     Other Fabricated Wire Product Manufacturing (NAICS code
332618).
     Machine Shops (NAICS code 332710).
     Precision Turned Product Manufacturing (NAICS code
332721).
     Bolt, Nut, Screw, Rivet, and Washer Manufacturing (NAICS
code 332722).
     Metal Heat Treating (NAICS code 332811).
     Metal Coating, Engraving (except Jewelry and Silverware),
and Allied Services to Manufacturers (NAICS code 332812).

     Electroplating, Plating, Polishing, Anodizing, and
Coloring (NAICS code 332813).
     Oil and Gas Field Machinery and Equipment Manufacturing
(NAICS code 333132).
     Cutting Tool and Machine Tool Accessory Manufacturing
(NAICS code 333515).
     Small Arms, Ordnance, and Ordnance Accessories
Manufacturing (NAICS code 332994).
     Fluid Power Pump and Motor Manufacturing (NAICS code
333996).
     All Other Miscellaneous Fabricated Metal Product
Manufacturing (NAICS code 332999).
     Oil and Gas Field Machinery and Equipment Manufacturing
(NAICS code 333132).
     Industrial and Commercial Fan and Blower and Air
Purification Equipment Manufacturing (NAICS code 333413).
     Cutting Tool and Machine Tool Accessory Manufacturing
(NAICS code 333515).
     Pump and Pumping Equipment Manufacturing (NAICS code
333911).
     Fluid Power Pump and Motor Manufacturing (NAICS code
333996).
     Search, Detection, Navigation, Guidance, Aeronautical, and
Nautical System and Instrument Manufacturing (NAICS code 334511).
     Automatic Environmental Control Manufacturing for
Residential, Commercial, and Appliance Use (NAICS code 334512).
     Motor and Generator Manufacturing (NAICS code 335312).
     Primary Battery Manufacturing (NAICS code 335912).
     Carbon and Graphite Product Manufacturing (NAICS code
335991).
     Motor Vehicle Brake System Manufacturing (NAICS code
336340).
     Aircraft Manufacturing (NAICS code 336411).
     Other Aircraft Parts and Auxiliary Equipment Manufacturing
(NAICS code 336413).
     Guided Missile and Space Vehicle Manufacturing (NAICS code
336414).
     Ship Building and Repairing (NAICS code 336611).
     Dental Equipment and Supplies Manufacturing (NAICS code
339114).
     Other Chemical and Allied Products Merchant Wholesalers
(NAICS code 424690).
     Petroleum Bulk Stations and Terminals (NAICS code 424710).
     Hazardous Waste Treatment and Disposal (NAICS code
562211).
     Solid Waste Combustors and Incinerators (NAICS code
562213).
    This action may also affect certain entities through pre-existing
import certification and export notification rules under TSCA. Persons
who import any chemical substance governed by a final TSCA section 6(a)
rule are subject to the TSCA section 13 (15 U.S.C. 2612) import
certification requirements and the corresponding regulations at 19 CFR
12.118 through 12.127; see also 19 CFR 127.28. Those persons must
certify that the shipment of the chemical substance complies with all
applicable rules and orders under TSCA. The EPA policy in support of
import certification appears at 40 CFR part 707, subpart B. In
addition, any persons who export or intend to export a chemical
substance that is the subject of this proposed rule are subject to the
export notification provisions of TSCA section 12(b) (15 U.S.C.
2611(b)), and must comply with the export notification requirements in
40 CFR part 707, subpart D.
    If you have any questions regarding the applicability of this
proposed action to a particular entity, consult the technical
information contact listed under FOR FURTHER INFORMATION CONTACT.

B. What is the Agency's authority for taking this action?

    Under TSCA section 6(a) (15 U.S.C. 2605(a)), if EPA determines
after risk evaluation that a chemical substance presents an
unreasonable risk of injury to health or the environment, without
consideration of costs or other non-risk factors, including an
unreasonable risk to a potentially exposed or susceptible subpopulation
identified as relevant to the risk evaluation, under the conditions of
use, EPA must by rule apply one or more requirements to the extent
necessary so that the chemical substance or mixture no longer presents
such risk.
    For a chemical substance listed in the 2014 update to the TSCA Work
Plan for Chemical Assessments for which a completed risk assessment was
published prior to the date of enactment of the Frank R. Lautenberg
Chemical Safety for the 21st Century Act, TSCA section 26(l)(4)
expressly authorizes EPA to issue rules under TSCA section 6(a) that
are consistent with the scope of the completed risk assessment and
consistent with the other applicable requirements of TSCA section 6.
TCE is such a chemical substance. It is listed in the 2014 update to
the TSCA Work Plan and the completed risk assessment was published on
June 25, 2014. The scope of the completed risk assessment includes
vapor degreasing.

C. What action is the Agency taking?

    EPA's proposed determination is that the use of TCE in vapor
degreasing presents an unreasonable risk of injury to health.
Accordingly, EPA is proposing under TSCA section 6 to prohibit the
manufacture (including import), processing, and distribution in
commerce of TCE for use in vapor degreasing; to prohibit commercial use
of TCE in vapor degreasing; and to require manufacturers, processors,
and distributors, except for retailers, to provide downstream
notification of this prohibition throughout the supply chain (e.g., via
a Safety Data Sheet (SDS)), and to keep records. The application of
this supply chain approach is necessary so that TCE no longer presents
the identified unreasonable risks. EPA is requesting public comment on
this proposal.
    This proposal is related to the proposed rule on TCE aerosol
degreasing and spot cleaning in dry cleaning facilities that published
in the Federal Register on December 16, 2016 (81 FR 91592) (FRL-9949-
86) (Ref. 1). This proposal and the earlier proposal together address
risks for workers and consumers associated with exposure to TCE through
inhalation that were identified in the 2014 TCE risk assessment and EPA
intends to finalize both actions together.

D. Why is the Agency taking this action?

    Based on EPA's analysis of worker exposures to TCE, EPA's proposed
determination is that the use of TCE in vapor degreasing presents an
unreasonable risk to human health. More specifically, this use results
in significant non-cancer risks under both acute and chronic exposure
scenarios and significant cancer risks from chronic exposures. These
adverse health effects include those resulting from developmental
toxicity (e.g., cardiac malformations, developmental immunotoxicity,
developmental neurotoxicity, fetal death), toxicity to the kidney
(kidney damage and kidney cancer), immunotoxicity (such as systemic
autoimmune diseases, e.g., scleroderma, and severe hypersensitivity
skin disorder), non-Hodgkin's lymphoma, reproductive and endocrine
effects (e.g., decreased libido and potency), neurotoxicity (e.g.,
trigeminal neuralgia), and toxicity to the liver (impaired functioning
and liver cancer) (Ref. 2). TCE may cause fetal cardiac malformations
that begin in utero. Cardiac malformations can be irreversible and
impact a person's health for a lifetime. In addition, fetal death,
possibly resulting from cardiac malformation, can be caused by exposure
to TCE. In utero exposure to TCE may cause other effects, such as
damage to the developing immune system, which manifest later in adult

life and can have long-lasting health impacts. Certain effects that
follow adult exposures, such as kidney and liver cancer, may develop
many years after initial exposure.
    As discussed in Unit I.C., EPA is not proposing to prohibit all
manufacturing, processing, distribution in commerce, and use of TCE. As
such, the application of this proposal's supply chain approach tailored
to specific uses that present unreasonable risks to human health is
necessary so that the chemical substance no longer presents the
identified unreasonable risks.

E. What are the estimated incremental impacts of this action?

    EPA has evaluated the potential costs of multiple regulatory
options, including the proposed approach of prohibiting the manufacture
(including import), processing, and distribution in commerce of TCE for
use in vapor degreasing; prohibiting the commercial use of TCE in vapor
degreasing; and requiring manufacturers, processors, and distributors,
except for retailers, to provide downstream notification of these
prohibitions throughout the supply chain as well as associated
recordkeeping requirements. This analysis (Ref. 3), which is available
in the docket, is discussed in Unit VI., and is briefly summarized
here.
    Alternatives to TCE with similar performance characteristics are
readily available. Most of the costs of the rule would be borne by
commercial users of TCE in vapor degreasing equipment, because they
would have to switch solvents and likely equipment as well. EPA has
estimated that the costs to users range from $30M to $45M when
annualized over 20 years at a 3% discount rate, and from $32M to $46M
over 20 years at a 7% discount rate. These are the total estimated
costs of this proposal. The costs of the downstream notification and
recordkeeping requirements to manufacturers, processors, and
distributors of TCE, estimated to be approximately $3,200 and $4,400
annualized over 20 years using 3% and 7% discount rates respectively.
For additional information see Unit 5.1.3 of the Economic Analysis.
(Ref. 3) However, because these notification and recordkeeping costs
were already accounted for in the economic analysis accompanying the
earlier TCE proposal (Ref. 1), they are not included in the total costs
for this proposal. EPA accounted for these costs in the prior proposal
because it believes the universe of entities distributing TCE for both
sets of uses are the same. EPA is taking comment on whether the same
firms distribute TCE for these two sets of uses.
    Although TCE causes a wide range of non-cancer adverse effects and
cancer, monetized benefits included only benefits associated with
reducing cancer risks. The Agency does not have sufficient information
to include a quantification or valuation estimate for non-cancer
benefits in the overall benefits at this time. The monetized benefits
for the proposed approach range from approximately $65 to $443 million
on an annualized basis over 20 years at 3% and $31 million to $225
million at 7% (Ref. 3). The non-monetized benefits resulting from the
prevention of the non-cancer adverse effects associated with TCE
exposure from use in vapor degreasers include developmental toxicity,
toxicity to the kidney, immunotoxicity, reproductive and endocrine
effects, neurotoxicity, and toxicity to the liver (Ref. 2). Some of the
effects that can be caused by exposure to TCE, such as cardiac
malformations and fetal death, occur in utero and can impact a person
for a lifetime; other effects, such as damage to the developing immune
system, may first manifest when a person is an adult and can have long
lasting impacts. Also see Unit VI.D.

F. Children's Environmental Health

    This action is consistent with the 1995 EPA Policy on Evaluating
Health Risks to Children (http://www.epa.gov/children/epas-policy-evaluating-risk-children). EPA has identified women of childbearing age
and the developing fetus as a susceptible subpopulation relevant to its
risk assessment for TCE. After evaluating the developmental toxicity
literature for TCE, the Integrated Risk Information System (IRIS) TCE
assessment concluded that fetal heart malformations are the most
sensitive developmental toxicity endpoint associated with TCE
inhalation exposure (Ref. 4). In its TSCA Chemical Work Plan Risk
Assessment for TCE, EPA identified developmental toxicity as the most
sensitive endpoint for TCE inhalation exposure (i.e., fetal heart
malformations) for the most sensitive human life stage (i.e., women of
childbearing age between the ages of 16 and 49 years and the developing
fetus) (Ref. 2). EPA used developmental toxicity endpoints for both the
acute and chronic non-cancer risk assessments based on its
developmental toxicity risk assessment policy that a single exposure of
a chemical within a critical window of fetal development may produce
adverse developmental effects (Ref. 5). For the identified susceptible
subpopulations, the proposed regulatory action is protective of the
fetal heart malformation endpoint and, for the exposed population as a
whole, the proposal is also protective of cancer risk. In addition, the
supporting non-cancer risk analysis of children and women of
childbearing age conducted in the TSCA Chemical Work Plan Risk
Assessment for TCE (Ref. 2) also meets the 1995 EPA Policy on
Evaluating Health Risks to Children (Ref. 6). Supporting information on
TCE exposures and the health effects of TCE exposure on children are
also available in the IRIS Toxicological Review of Trichloroethylene
(Ref. 4) and the TSCA Chemical Work Plan Risk Assessment on
Trichloroethylene (Ref. 2), as well as Unit VI of this preamble.

II. Overview of TCE and the Use Subject to This Proposed Rule

A. What chemical is included in the proposed rule?

    This proposed rule applies to TCE (Chemical Abstract Services
Registry Number 79-01-6) for use in vapor degreasing.

B. What are the uses of TCE?

    In 2011, global consumption of TCE was 945 million pounds and
consumption in the United States was 255 million pounds. TCE is
produced within and imported into the United States. Nine companies,
including domestic manufacturers and importers, reported a total
production and import of 225 million pounds of TCE in 2011 to EPA
pursuant to the Chemical Data Reporting (CDR) rule (Ref. 2).
    The majority (about 83.6%) of TCE is used as an intermediate
chemical for manufacturing refrigerant HFC[hyphen]134a. This use occurs
in a closed system that has low potential for human exposure (Ref. 2).
EPA did not assess this use and is not proposing to regulate this use
of TCE under TSCA at this time. However, this does not mean that EPA
found that this use or other uses not included in the TCE risk
assessment present low risk. Much of the remainder, about 14.7%, is
used as a solvent for degreasing of metals. A relatively small
percentage, about 1.7%, accounts for all other uses, including TCE use
in products, such as aerosol degreasers.
    Based on the Toxics Release Inventory (TRI) data for 2012, 38
companies used TCE as a formulation component, 33 companies processed
TCE by repackaging the chemical, 28 companies used TCE as a
manufacturing aid, and 1,113 companies used TCE for ancillary uses,
such as degreasing (Ref. 2). Based on the latest TRI data from 2014,
the number of users of TCE has significantly

decreased since 2012: 24 companies use TCE as a formulation component,
20 companies process TCE by repackaging the chemical, 20 companies use
TCE as a manufacturing aid, and 97 companies use TCE for ancillary
uses, such as degreasing. The TRI data does not represent all of the
facilities manufacturing, processing, and/or using TCE because only
certain industries and types of facilities are required to report. EPA
estimates that there are 2,632 to 6,232 firms using TCE for vapor
degreasing in the U.S. (Ref. 3).
    The use assessed by EPA that is the subject of this proposal,
commercial use of TCE in vapor degreasing, is estimated to represent up
to 14.7% of total use of TCE. This use is discussed in detail in Unit
VI.

C. What are the potential health effects of TCE?

    A broad set of relevant studies including epidemiologic studies,
animal bioassays, metabolism studies, and mechanistic studies show that
TCE exposure is associated with an array of adverse health effects. TCE
has the potential to induce developmental toxicity, immunotoxicity,
kidney toxicity, reproductive and endocrine effects, neurotoxicity,
liver toxicity, and several forms of cancer (Ref. 2).
    TCE is fat soluble (lipophilic) and easily crosses biological
membranes. TCE has been found in human maternal and fetal blood and in
the breast milk of lactating women (Ref. 2). EPA's IRIS assessment
(Ref. 4) concluded that TCE poses a potential health hazard for non-
cancer toxicity including fetal heart malformations and other
developmental effects, immunotoxicity, kidney toxicity, reproductive
and endocrine effects, neurotoxicity, and liver effects. The IRIS
assessment also evaluated TCE and its metabolites. Based on the results
of in vitro and in vivo tests, TCE metabolites have the potential to
bind or induce damage to the structure of deoxyribonucleic acid (DNA)
or chromosomes (Ref. 4).
    An evaluation of the overall weight of the evidence of the human
and animal developmental toxicity data suggests an association between
pre[hyphen] and/or post-natal TCE exposures and potential adverse
developmental outcomes. TCE[hyphen]induced heart malformations and
immunotoxicity in animals have been identified as the most sensitive
developmental toxicity endpoints for TCE. Human studies examined the
possible association of TCE with various prenatal effects. These
adverse effects of developmental TCE exposure may include: Death
(spontaneous abortion, perinatal death, pre- or post-implantation loss,
resorptions); decreased growth (low birth weight, small for gestational
age); congenital malformations, in particular heart defects; and
postnatal effects such as reduced growth, decreased survival,
developmental neurotoxicity, developmental immunotoxicity, and
childhood cancers. Some epidemiological studies reported an increased
incidence of birth defects in TCE[hyphen]exposed populations from
exposure to contaminated water. As for human developmental
neurotoxicity, studies collectively suggest that the developing brain
is susceptible to TCE toxicity. These studies have reported an
association with TCE exposure and central nervous system birth defects
and postnatal effects such as delayed newborn reflexes, impaired
learning or memory, aggressive behavior, hearing impairment, speech
impairment, encephalopathy, impaired executive and motor function and
attention deficit disorder (Ref. 2).
    Immune[hyphen]related effects following TCE exposures have been
observed in adult animal and human studies. In general, these effects
were associated with enhanced immune response as opposed to
immunosuppressive effects. Human studies have reported a relationship
between systemic autoimmune diseases, such as scleroderma, with
occupational exposure to TCE. There have also been a large number of
case reports in TCE[hyphen]exposed workers developing a severe
hypersensitivity skin disorder, often accompanied by systemic effects
to the lymph nodes and other organs, such as hepatitis (Ref. 2).
    Studies in both humans and animals have shown changes in the
proximal tubules of the kidney following exposure to TCE (Ref. 2). The
IRIS TCE assessment concluded that TCE is carcinogenic to humans based
on convincing evidence of a causal relationship between TCE exposure in
humans and kidney cancer (Ref. 4). A recent review of TCE by the
International Agency for Research on Cancer (IARC) also supported this
conclusion (Ref. 7). The 12th report on carcinogens (RoC) by the
National Toxicology Program also concluded that TCE is reasonably
anticipated to be a human carcinogen 2015 (Ref. 8). These additional
recent peer reviews are consistent with EPA's classification that TCE
is carcinogenic to humans by all routes of exposures based upon strong
epidemiological and animal evidence (Refs. 2, 4).
    TCE metabolites appear to be the causative agents that induce renal
toxicity, including cancer.
S[hyphen]dichlorovinyl[hyphen]L[hyphen]cysteine (DCVC), and to a lesser
extent other metabolites, appears to be responsible for kidney damage
and kidney cancer following TCE exposure. Toxicokinetic data suggest
that the TCE metabolites derived from glutathione conjugation (in
particular DCVC) can be systemically delivered or formed in the kidney.
Moreover, DCVC[hyphen]treated animals showed the same type of kidney
damage as those treated with TCE (Ref. 2). The toxicokinetic data and
the genotoxicity of DCVC further suggest that a mutagenic mode of
action is involved in TCE[hyphen]induced kidney tumors, although
cytotoxicity followed by compensatory cellular proliferation cannot be
ruled out. As for the mutagenic mode of action, both genetic
polymorphisms (Glutathione transferase (GST) pathway) and mutations to
tumor suppressor genes have been hypothesized as possible mechanistic
key events in the formation of kidney cancers in humans (Ref. 2).
    The toxicological literature provides support for male and female
reproductive effects following TCE exposure. Both the epidemiological
and animal studies provide evidence of adverse effects to female
reproductive outcomes. However, more extensive evidence exists in
support of an association between TCE exposures and male reproductive
toxicity. There is evidence that metabolism of TCE in male reproductive
tract tissues is associated with adverse effects on sperm measures in
both humans and animals. Furthermore, human studies support an
association between TCE exposure and alterations in sperm density and
quality, as well as changes in sexual drive or function and altered
serum endocrine levels (Ref. 2).
    Neurotoxicity has been demonstrated in animal and human studies
under both acute and chronic exposure conditions. Evaluation of
multiple human studies revealed TCE[hyphen]induced neurotoxic effects
including alterations in trigeminal nerve and vestibular function,
auditory effects, changes in vision, alterations in cognitive function,
changes in psychomotor effects, and neurodevelopmental outcomes. These
studies in different populations have consistently reported vestibular
system[hyphen]related symptoms such as headaches, dizziness, and nausea
following TCE exposure (Ref. 2).
    Animals and humans exposed to TCE consistently experience liver
toxicity. Specific effects include the following structural changes:
Increased liver weight, increased DNA synthesis (transient), enlarged
hepatocytes, enlarged nuclei, and peroxisome proliferation. Several
human studies

reported an association between TCE exposure and significant changes in
serum liver function tests used in diagnosing liver disease, or changes
in plasma or serum bile acids. There was also human evidence for
hepatitis accompanying immune[hyphen]related generalized skin diseases,
jaundice, hepatomegaly, hepatosplenomegaly, and liver failure in
TCE[hyphen]exposed workers (Ref. 2).
    TCE is characterized as carcinogenic to humans by all routes of
exposure as documented in EPA's IRIS TCE assessment (Ref. 4). This
conclusion is based on strong cancer epidemiological data that reported
an association between TCE exposure and the onset of various cancers,
primarily in the kidney, liver, and the immune system, i.e.,
non[hyphen]Hodgkin's lymphoma (NHL). Further support for TCE's
characterization as a carcinogen comes from positive results in
multiple rodent cancer bioassays in rats and mice of both sexes,
similar toxicokinetics between rodents and humans, mechanistic data
supporting a mutagenic mode of action for kidney tumors, and the lack
of mechanistic data supporting the conclusion that any of the mode(s)
of action for TCE[hyphen]induced rodent tumors are irrelevant to
humans. Additional support comes from the 2014 evaluation of TCE's
carcinogenic effects by IARC, which classifies TCE as carcinogenic to
humans (Ref. 7). The 12th NTP RoC also concluded that TCE exposure is
reasonably anticipated to be a human carcinogen (Ref. 8). These
additional recent peer reviewed documents are consistent with EPA's
classification that TCE is carcinogenic to humans by all routes of
exposures based upon strong epidemiological and animal evidence (Refs.
2, 4).

D. What are the environmental impacts of TCE?

    Pursuant to TSCA section 6(c), this unit describes the effects of
TCE on the environment and the magnitude of the exposure of the
environment to TCE. The unreasonable risk determination of this
proposal is based solely on risks to human health since those risks are
the most serious consequence of use of TCE and are sufficient to
support this proposed action. The following is a discussion of the
environmental impacts of TCE.
    1. Environmental effects and impacts. TCE enters the environment as
a result of emissions from metal degreasing facilities, and spills or
accidental releases, and historic waste disposal activities. Because of
its high vapor pressure and low affinity for organic matter in soil,
TCE evaporates fairly rapidly when released to soil; however, where it
is released onto land surface or directly into the subsurface, TCE can
migrate from soil to groundwater. Based on TCE's moderate persistence,
low bioaccumulation, and low hazard for aquatic toxicity, the magnitude
of potential environmental impacts on ecological receptors is judged to
be low for the environmental releases associated with the use of TCE
for vapor degreasing. This should not be misinterpreted to mean that
the fate and transport properties of TCE suggest that water and soil
contamination is likely low or does not pose an environmental concern.
EPA is addressing TCE contamination in groundwater, drinking water, and
contaminated soils at a large number of sites. While the primary
concern with this contamination has been human health, there is
potential for TCE exposures to ecological receptors in some cases (Ref.
2).
    2. What is the global warming potential of TCE? Global warming
potential (GWP) measures the potency of a greenhouse gas over a
specific period of time, relative to carbon dioxide, which has a high
GWP of 1 regardless of the time period used. Due to high variability in
the atmospheric lifetime of greenhouse gases, the 100-year scale
(GWP100) is typically used. TCE has relatively low global warming
potential at a GWP100 of 140 and thus the impact is low (Ref. 2).
    3. What is the ozone depletion potential of TCE? TCE is not an
ozone-depleting substance and is listed as acceptable under the
Significant New Alternatives Policy (SNAP) program for degreasing and
aerosols. In 2007, TCE was identified as a substitute for two ozone
depleting chemicals, methyl chloroform and CFC-113, for metals,
electronics, and precision cleaning (72 FR 30142, May 30, 2007) (FRL-
8316-8) (Ref. 9).
    4. Is TCE a volatile organic compound (VOC)? TCE is a VOC as
defined at 40 CFR 51.100(c). A VOC is any compound of carbon, excluding
carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or
carbonates, and ammonium carbonate, which participates in atmospheric
photochemical reactions.
    5. Does TCE persist in the environment and bioaccumulate? TCE may
be persistent, but it is not bioaccumulative. TCE is slowly degraded by
sunlight and reactants when released to the atmosphere. Volatilization
and microbial biodegradation influence the fate of TCE when released to
water, sediment or soil. The biodegradation of TCE in the environment
is dependent on a variety of factors and so a wide range of degradation
rates have been reported (ranging from days to years). TCE is not
expected to bioconcentrate in aquatic organisms based on measured
bioconcentration factors of less than 1000 (Ref. 2).

III. Regulatory Actions Pertaining to TCE

    Because of its potential health effects, TCE is subject to state,
federal, and international regulations restricting and regulating its
use, which are summarized in this unit. None of these actions addresses
the unreasonable risks under TSCA that EPA is seeking to address in
this proposed rule.

A. Federal Actions Pertaining to TCE

    Since 1979, EPA has issued numerous rules and notices pertaining to
TCE under its various authorities.
     Toxic Substances Control Act: On December 16, 2016, EPA
issued a proposed rule under TSCA section 6 to prohibit the manufacture
(including import), processing, distribution in commerce and commercial
use of TCE in aerosol degreasers and as a spot removal agent in dry
cleaning facilities (Ref. 1). In addition, EPA published a final
Significant New Use Rule (SNUR) that would require manufacturers
(including importers) and processors of TCE to notify the Agency before
starting or resuming any significant new uses of TCE in certain
consumer products, including in spray fixatives used to finish arts and
crafts (81 FR 20535, April 8, 2016) (Ref. 10).
     Safe Drinking Water Act: EPA has issued drinking water
standards for TCE pursuant to section 1412 of the Safe Drinking Water
Act. EPA promulgated the National Primary Drinking Water Regulation
(NPDWR) for TCE in 1987 (52 FR 25690, July 8, 1987). The NPDWR
established a non-enforceable maximum contaminant level (MCL) goal of
zero milligrams per liter (mg/L) based on classification as a probable
human carcinogen. The NPDWR also established an enforceable MCL of
0.005 mg/L. EPA is evaluating revising the TCE drinking water standard
as part of a group of carcinogenic volatile organic compounds.
     Clean Water Act: EPA identified TCE as a toxic pollutant
under section 307(a)(1) of the Clean Water Act (33 U.S.C. 1317(a)(1))
in 1979 (44 FR 44502, July 30, 1979) (FRL-1260-5). In addition, EPA
developed recommended TCE ambient water quality criteria for the
protection of human health pursuant to section 304(a) of the Clean
Water Act.
     Clean Air Act: TCE is a hazardous air pollutant (HAP)
under the Clean Air Act (42 U.S.C. 7412(b)(1). EPA

promulgated National Emission Standards for Hazardous Air Pollutants
(NESHAPs) for TCE for several industrial source categories, including
halogenated solvent cleaning, fabric printing, coating, and dyeing, and
synthetic organic chemical manufacturing. The halogenated solvent
cleaning NESHAP, controls emissions of several halogenated solvents,
including TCE, from halogenated solvent cleaning machines (40 CFR
subpart T). The NESHAP includes multiple compliance alternatives to
allow maximum compliance flexibility. In 2007, EPA promulgated the
Halogenated Solvent Cleaning NESHAP RTR (Risk and Technology Review)
Rule (72 FR 25138, May 3, 2007) (FRL-8303-6), in which EPA evaluated
the health and environmental risks remaining after promulgation of the
original NESHAP and established revised standards that further limit
emissions of TCE (and other solvents) in halogenated solvent cleaning.
Specifically, EPA promulgated a facility-wide emission limit of 60,000
kilograms per year (kg/year) methylene chloride equivalent, a unit
which combines emissions of methylene chloride, trichloroethylene, and
perchloroethylene. The facility-wide emission limit applied to all
halogenated solvent cleaning machines with the exception of halogenated
solvent cleaning machines used by the following industries: Facilities
that manufacture narrow tubing, facilities that use continuous web
cleaning machines, aerospace manufacturing and maintenance facilities,
and military maintenance and depot facilities. EPA also promulgated a
facility-wide emission limit of 100,000 kg/year methylene chloride
equivalent for halogenated solvent cleaning machines used at military
maintenance and depot facilities. TCE is also regulated under the
NESHAP rule for synthetic organic chemical manufacturing. This rule
consists of four subparts in 40 CFR part 63. In 2003, EPA issued a
final NESHAP rule to reduce toxic air pollutant emissions from fabric
and other textile coating, printing, and dyeing facilities. The final
rule applied to new and existing facilities that emit 10 tons per year
or more of a single toxic air pollutant listed in the Clean Air Act or
25 tons per year or more of a combination of those pollutants,
including TCE. In addition, EPA has established VOC standards for
consumer products under section 183(e) of the Clean Air Act.
     Resource Conservation and Recovery Act (RCRA): EPA
classifies certain wastes containing TCE as hazardous waste subject to
Subtitle C of RCRA pursuant to the toxicity characteristics or as a
listed waste. RCRA also provides authority to require cleanup of
hazardous wastes containing TCE at RCRA facilities.
     Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA): EPA designated TCE as a hazardous substance
with a reportable quantity pursuant to section 102(a) of CERCLA and EPA
is actively overseeing cleanup of sites contaminated with TCE pursuant
to the National Contingency Plan (NCP). While many of the statutes that
EPA is charged with administering provide statutory authority to
address specific sources and routes of TCE exposure, none of these can
address the serious human health risks from TCE exposure that EPA is
proposing to address under TSCA section 6(a) with this proposed rule.
    The Occupational Safety and Health Administration (OSHA)
established a permissible exposure limit (PEL) for TCE in 1971. The PEL
is an 8-hour time-weighted average (TWA) TCE concentration of 100 ppm.
In addition, the TCE PEL requires that exposure to TCE not exceed 200
ppm (ceiling) at any time during an eight hour work shift with the
following exception: Exposures may exceed 200 ppm, but not more than
300 ppm (peak), for a single time period up to 5 minutes in any 2 hours
(Ref. 11). OSHA acknowledges that many of its PELs are not sufficiently
protective of worker health. OSHA has noted that ``with few exceptions,
OSHA's PELs, which specify the amount of a particular chemical
substance allowed in workplace air, have not been updated since they
were established in 1971 under expedited procedures available in the
short period after the OSH Act's adoption . . . Yet, in many instances,
scientific evidence has accumulated suggesting that the current limits
are not sufficiently protective'' (Ref. 12 at p. 61386), including the
PEL for TCE.
    To provide employers, workers, and other interested parties with a
list of alternate occupational exposure limits that may serve to better
protect workers, OSHA's Web page highlights selected occupational
exposure limits derived by other organizations. For example, the
National Institute for Occupational Safety and Health considers TCE a
potential occupational carcinogen and recommended an exposure limit of
25 ppm as a 10-hour TWA in 2003 (Ref. 13). The American Conference of
Governmental Industrial Hygienists recommended an 8-hour TWA of 10 ppm
and an acute, or short term, exposure limit of 25 ppm in 2004 (Ref.
14).

B. State Actions Pertaining to TCE

    Many states have taken actions to reduce risks from TCE use. TCE is
listed on California's Safer Consumer Products regulations candidate
list of chemicals that exhibit a hazard trait and are on an
authoritative list and is also listed on California's Proposition 65
list of chemicals known to cause cancer or birth defects or other
reproductive harm. In addition, the California Code of Regulations,
Title 17, Section 94509(a) lists standards for VOCs for consumer
products sold, supplied, offered for sale, or manufactured for use in
California (Ref. 15). As part of that regulation, use of consumer
general purpose degreaser products that contain TCE are banned in
California and safer substitutes are in use.
    In Massachusetts, TCE is a designated high hazard substance, with
an annual reporting threshold of 1,000 pounds (Ref. 16). Minnesota
classifies TCE as a chemical of high concern (Ref. 17). Many other
states have considered TCE for similar chemical listings (Ref. 18).
Several additional states have various TCE regulations that range from
reporting requirements to product contamination limits to use reduction
efforts aimed at limiting or prohibiting TCE content in products.
    Most states have set PELs identical to the OSHA 100 ppm 8-hour TWA
PEL (Ref. 18). Nine states have PELs of 50 ppm (Ref. 18). California's
PEL of 25 ppm is the most stringent (Ref. 15). All of these PELs are
significantly higher than the exposure levels at which EPA identified
unreasonable risks for TCE use for vapor degreasing and would not be
protective.

C. International Actions Pertaining to TCE

    TCE is also regulated internationally and the international
industrial and commercial sectors have moved to alternatives. TCE was
added to the EU Registration, Evaluation, Authorisation and Restriction
of Chemicals (REACH) restriction of substances classified as a
carcinogen category 1B under the EU Classification and Labeling
regulation in 2009 (Ref. 19). The restriction prohibits the placing on
the market or use of TCE as a substance, as a constituent of other
substances, or in mixtures for supply to the general public when the
individual concentration of TCE in the substance or mixture is equal to
or greater than 0.1% by weight (Ref. 19). In 2010, TCE was added to the
Candidate List of substances for inclusion in Annex XIV of REACH, or
the Authorisation List. Annex XIV includes substances of very high
concern that are subject to use

authorization due to their hazardous properties. TCE meets the criteria
for classification as a carcinogen. In 2011, TCE was recommended for
inclusion in Annex XIV of REACH due to the very high volumes allocated
to uses in the scope of authorization and because at least some of the
described uses appeared to result in significant exposure of workers
and professionals, and could be considered widely dispersive uses.
    In 2013, the Commission added TCE to Annex XIV of REACH, making it
subject to authorization. As such, entities that wanted to use TCE were
required to apply for authorization by October 2014, and those entities
without an authorization were required to stop using TCE by April 2016.
The European Chemicals Agency (ECHA) received 19 applications for
authorization from entities interested in using TCE beyond April 2016.
Two of those were for vapor degreasing applications (Refs. 20, 21). In
each case, the opinion of the Committee for Risk Assessment was that it
was not possible to determine a derived no-effect level (DNEL) for the
carcinogenicity properties of the substance in accordance with REACH
and that the operational conditions and risk management measures in the
applications appeared not to limit the risk. Those measures included
use in a specific type of closed vapor degreasing system with personal
protective equipment (PPE). Final decisions have not yet been made on
the applications.
    Canada conducted a hazard assessment of TCE in 1993 and concluded
that ``trichloroethylene occurs at concentrations that may be harmful
to the environment, and that may constitute a danger in Canada to human
life or health. It has been concluded that trichloroethylene occurs at
concentrations that do not constitute a danger to the environment on
which human life depends'' (Ref. 22). In 2003, Canada issued the
Solvent Degreasing Regulations (SOR/2003-283) to reduce releases of TCE
into the environment from solvent degreasing facilities using more than
1,000 kilograms of TCE per year (Ref. 23). In 2013, Canada added TCE to
the Toxic Substances List--Schedule 1 because TCE ``is entering or may
enter the environment in a quantity or concentration or under
conditions that: (a) Have or may have an immediate or chronic harmful
effect on the environment or its biological diversity, and (c)
constitute or may constitute a danger in Canada to human life or
health.'' (Ref. 23).
    In Japan, the Chemical Substances Control Law considers TCE a Class
II substance (substances that may pose a risk of long[hyphen]term
toxicity to humans or to flora and fauna in the human living
environment, and that have been, or in the near future are reasonably
likely to be, found in considerable amounts over a substantially
extensive area of the environment) (Ref. 24). Japan also controls air
emissions and water discharges containing TCE, as well as aerosol
products for household use and household cleaners containing TCE.
    TCE is listed in the Australian National Pollutant Inventory, a
program run cooperatively by the Australian, State and Territory
governments to monitor common pollutants and their levels of release to
the environment. Australia classifies TCE as a health, physicochemical
and/or ecotoxicological hazard, according to the Australian National
Occupational Health and Safety Commission (Ref. 25).

IV. TCE Risk Assessment

    In 2013, EPA identified TCE use as a solvent degreaser (aerosol
degreasing and vapor degreasing) and spot remover in dry cleaning
operations as a priority for risk assessment under the TSCA Work Plan.
This Unit describes the development of the TCE risk assessment and
supporting analysis and expert input on vapor degreasing, the use that
is the subject of this proposed rule. A more detailed discussion of the
risks associated with TCE use in vapor degreasing can be found in Unit
VI.

A. TSCA Work Plan for Chemical Assessments

    In 2012, EPA released the TSCA Work Plan Chemicals: Methods
Document in which EPA described the process the Agency intended to use
to identify potential candidate chemicals for near-term review and
assessment under TSCA (Ref. 26). EPA also released the initial list of
TSCA Work Plan chemicals identified for further assessment under TSCA
as part of its chemical safety program (Ref. 27).
    The process for identifying these chemicals for further assessment
under TSCA was based on a combination of hazard, exposure, and
persistence and bioaccumulation characteristics, and is described in
the TSCA Work Plan Chemicals Methods Document (Ref. 26). Using the TSCA
Work Plan chemical prioritization criteria, TCE ranked high for health
hazards and exposure potential and was included on the initial list of
TSCA Work Plan chemicals for assessment.

B. TCE Risk Assessment

    EPA finalized a TSCA Work Plan Chemical Risk Assessment for TCE
(TCE risk assessment) in June 2014, following the July 2013 peer review
of the December 2012 draft TCE risk assessment. All documents from the
July 2013 peer review of the draft TCE risk assessment are available in
EPA Docket Number EPA-HQ-OPPT-2012-0723. TCE appears in the 2014 update
of the TSCA Work Plan for Chemical Assessments and the completed risk
assessment is noted therein. The TCE risk assessment evaluated
commercial and consumer use of TCE as a solvent degreaser (aerosol
degreasing and vapor degreasing), commercial use of TCE as a spotting
agent at dry cleaning facilities, and consumer use of TCE as a spray-
applied protective coating for arts and crafts (Ref. 2).
    The uses selected for the TCE risk assessment were chosen because
they were expected to involve frequent or routine use of TCE in high
concentrations and/or have high potential for human exposure (Ref. 2).
However, this does not mean that EPA found that other uses not included
in the TCE risk assessment present low risk.
    As described in the TCE risk assessment, solvent cleaning or
degreasing is widely used to remove grease, oils, waxes, carbon
deposits, fluxes, and tars from metal, glass, or plastic surfaces. With
respect to vapor degreasing, there are two general types of degreasing
machines: Batch and in[hyphen]line. Batch cleaning machines are the
most common type, while in[hyphen]line cleaners are typically used in
large[hyphen]scale industrial operations. There are a number of
variations of each general type of machine. Emissions from degreasing
machines typically result from:
     Evaporation of the solvent from the interface between the
solvent and the air,
     ``Carry out'' of excess solvent on cleaned parts, and
     Evaporative losses of the solvent during filling and
draining of the degreasing machine.
    In its assessment of vapor degreasing, the TCE risk assessment
concentrated on open top vapor degreasing machines because they are the
most prevalent, particularly for smaller operations. The risk
assessment identified acute and chronic non[hyphen]cancer risks for
workers who conduct TCE[hyphen]based solvent vapor degreasing at small
degreasing facilities, as well as occupational bystanders to those
activities. More specifically, the TCE risk assessment identified risks
for non-cancer developmental effects resulting from acute exposure. The
risk assessment also identified risks for a range of non-cancer health
effects resulting from chronic exposure. Within

this range of effects, the greatest risk is for developmental effects
(i.e., fetal cardiac defects), although there also are risks for kidney
effects and immunotoxicity. In addition, there are risks for adverse
reproductive effects, neurotoxicity, and liver toxicity associated with
chronic exposures (Ref. 2).
    Margins of exposure (MOEs) were used in this assessment to estimate
non-cancer risks for acute and chronic exposures. The MOE is the health
point of departure (an approximation of the no-observed adverse effect
level) for a specific endpoint divided by the exposure concentration
for the specific scenario of concern. The benchmark MOE accounts for
the total uncertainty factor based on the following uncertainty
factors: Intraspecies, interspecies, subchronic to chronic, and lowest
observed adverse effect level (LOAEL) to no-observed adverse effect
level (NOAEL). Uncertainty factors are intended to account for (1) the
variation in sensitivity among the members of the human population
(i.e., interhuman or intraspecies variability); (2) the uncertainty in
extrapolating animal data to humans (i.e., interspecies variability);
(3) the uncertainty in extrapolating from data obtained in a study with
less-than-lifetime exposure to lifetime exposure (i.e., extrapolating
from subchronic to chronic exposure); and (4) the uncertainty in
extrapolating from a LOAEL rather than from a NOAEL (Ref. 28). MOEs
provide a non-cancer risk profile by presenting a range of estimates
for different non-cancer health effects for different exposure
scenarios, and are a widely recognized method for evaluating a range of
potential non-cancer health risks from exposure to a chemical.
    The acute inhalation risk assessment used developmental toxicity
data to evaluate the acute risks for the TCE use scenarios. As
indicated in the TCE risk assessment, EPA's policy supports the use of
developmental studies to evaluate the risks of acute exposures. This
science-based policy presumes that a single exposure of a chemical at a
critical window of fetal development may produce adverse developmental
effects (Ref. 5). This is the case with cardiac malformation. EPA
reviewed multiple studies for suitability for acute risk estimation
including a number of developmental studies of TCE exposure and
additional developmental studies of TCE metabolites (Appendix N) (Ref.
2). EPA based its acute risk assessment on the most sensitive health
endpoint (i.e., fetal heart malformations) representing the most
sensitive human life stage (i.e., the developing fetus) (Ref. 2). The
acute risk assessment used the physiologically-based pharmacokinetic
(PBPK)[hyphen]derived hazard values (HEC50, HEC95, or HEC99; HECXX is
the Human Equivalent Concentration at a particular percentile) from the
Johnson et al. (2003) (Ref. 29) developmental toxicity study for each
vapor degreaser use scenario. Note that the differences among these
hazard values is small and no greater than 3[hyphen]fold (i.e.,
2[hyphen]fold for HEC50/HEC95 ratios; 3[hyphen]fold for HEC50/HEC99
ratios; 1.4[hyphen]fold for HEC95/HEC99 ratios). The IRIS TCE
assessment used the HEC99 for the non[hyphen]cancer
dose[hyphen]response derivations because the HEC99 was interpreted to
be protective for a sensitive individual in the population (Ref. 4).
While the HEC99 was used to find the level of risk to be used in making
the proposed TSCA section 6(a) determination, the small variation among
HEC50, HEC95 and HEC99 would not result in a different risk
determination.
    For non-cancer effects, EPA estimated exposures that are
significantly greater than the point of departure. The baseline cancer
risk is estimated to be 3.66 x 10-1 for users of open top
vapor degreasing systems.
    The levels of acute and chronic exposures estimated to present low
risk for non-cancer effects also result in low risk for cancer.
    Given these identified risks, EPA conducted an additional analysis
consistent with the scope of the TCE risk assessment to better
characterize the risk to workers and occupational bystanders from the
use of TCE in batch vapor degreasing machines as well as in two
different types of in-line systems (conveyor and continuous web
cleaning machines) (Ref. 30). This analysis also evaluated the exposure
reductions that would result from switching from an open-top vapor
degreasing system to a closed-loop vapor degreasing system. More
information on the different types of vapor degreasing machines can be
found in Unit VI.A.1. In the supplemental analysis, EPA identified
short-term and long-term non-cancer and cancer risks for all types of
vapor degreasing machines, although the risks for closed-loop machines
are estimated to be lower than for any of the other types (Ref. 30).

C. Stakeholder Input on TCE and Vapor Degreasing

    On July 29, 2014, EPA held a 2-day public workshop on TCE
degreasing (Ref. 31). The purpose of the workshop was to collect
information from users, academics, and other stakeholders on the use of
TCE as a degreaser in various applications, e.g., in degreasing metal
parts, availability and efficacy of safer alternatives, safer
engineering practices and technologies to reduce exposure to TCE, and
to discuss possible risk reduction approaches. The workshop included
presentations by experts, breakout sessions with case studies, and
public comment opportunities (Ref. 31) and informed EPA's assessment of
the alternatives to TCE considered in this proposed rule. All documents
from the public workshop are available in EPA Docket Number EPA-HQ-
OPPT-2014-0327. Informed in part by the workshop and other analysis,
including discussion with the Toxics Use Reduction Institute at the
University of Massachusetts Lowell, EPA has concluded that TCE
alternatives are available for all applications subject to this
proposed rule as well as EPA's earlier proposal (Ref. 1). The
discussions at the public workshop demonstrated that alternatives are
available for the vapor degreasing uses that are being addressed in
this proposed rulemaking.
    On June 1, 2016, EPA convened a Small Business Advocacy Review
(SBAR) Panel on TCE in vapor degreasing. The Panel solicited input from
eighteen Small Entity Representatives (SERs) and made several
recommendations on aspects of this rulemaking. The Panel process,
including the final report of the Panel (Ref. 32), is discussed in Unit
XII.

V. Regulatory Approach

A. TSCA Section 6 Unreasonable Risk Analysis

    Under TSCA section 6(a), if the Administrator determines that a
chemical substance presents an unreasonable risk of injury to health or
the environment, without consideration of costs or other non-risk
factors, including an unreasonable risk to a potentially exposed or
susceptible subpopulation identified as relevant to the Agency's risk
evaluation, under the conditions of use, EPA must by rule apply one or
more requirements to the extent necessary so that the chemical
substance no longer presents such risk.
    The TSCA section 6(a) requirements can include one or more, or a
combination of, the following actions:
     Prohibit or otherwise restrict the manufacturing,
processing, or distribution in commerce of such substances (Sec.
6(a)(1)).
     Prohibit or otherwise restrict manufacturing, processing,
or distribution in commerce of such substances for particular uses or
for uses in excess of a specified concentration (Sec.  6(a)(2)).

     Require minimum warning labels and instructions (Sec.
6(a)(3)).
     Require record keeping or testing (Sec.  6(a)(4)).
     Prohibit or regulate any manner or method of commercial
use (Sec.  6(a)(5)).
     Prohibit or otherwise regulate any manner or method of
disposal (Sec.  6(a)(6)).
     Direct manufacturers and processors to give notice of the
determination to distributors and the public and replace or repurchase
substances (Sec.  6(a)(7)).
    EPA analyzed a wide range of regulatory options under TSCA section
6(a) in order to select the proposed regulatory approach. EPA
considered whether a regulatory option (or combination of options)
would address the identified unreasonable risks so that the chemical
substance no longer presents such risks. To do so, EPA initially
analyzed whether the regulatory options could reduce risks (non-cancer
and cancer) to levels below those of concern, based on EPA's technical
analysis of exposure scenarios. For the non-cancer risks, EPA found an
option could be protective against the risk if it could achieve the
benchmark MOE for the most sensitive non-cancer endpoint. EPA's
assessments for these uses indicate that when exposures meet the
benchmark MOE for the most sensitive endpoint, they also result in low
risk for cancer.
    After the technical analysis, which represents EPA's assessment of
the potential for the regulatory options to achieve risk benchmarks
based on analysis of exposure scenarios, EPA then considered how
reliably the regulatory options would actually reach these benchmarks.
For the purposes of this proposal, EPA found that an option addressed
the risk so that it was no longer unreasonable if the option could
achieve the benchmark MOE or cancer benchmark for the most sensitive
endpoint. In evaluating whether a regulatory option would ensure that
the chemical substance no longer presents the identified unreasonable
risks, the Agency considered whether the option could be realistically
implemented or whether there were practical limitations on how well the
option would mitigate the risks in relation to the benchmarks, as well
as whether the option's protectiveness was impacted by environmental
justice or children's health concerns.

B. TSCA Section 6(c)(2) Considerations

    TSCA section 6(c)(2) requires EPA to consider and publish a
statement based on reasonably available information with respect to
the:
     Health effects of the chemical substance or mixture (in
this case, TCE) and the magnitude of human exposure to TCE;
     Environmental effects of TCE and the magnitude of exposure
of the environment to TCE;
     Benefits of TCE for various uses;
     Reasonably ascertainable economic consequences of the
rule, including: The likely effect of the rule on the national economy,
small business, technological innovation, the environment, and public
health; the costs and benefits of the proposed and final rule and of
the one or more primary alternatives that EPA considered; and the cost
effectiveness of the proposed rule and of the one or more primary
alternatives that EPA considered.
    In addition, in selecting among prohibitions and other restrictions
available under TSCA section 6(a), EPA must factor in, to the extent
practicable, these considerations. Further, in deciding whether to
prohibit or restrict in a manner that substantially prevents a specific
condition of use of a chemical substance or mixture, and in setting an
appropriate transition period for such action, EPA must also consider,
to the extent practicable, whether technically and economically
feasible alternatives that benefit health or the environment will be
reasonably available as a substitute when the proposed prohibition or
other restriction takes effect.
    EPA's analysis of the health effects of and magnitude of exposure
to TCE can be found in Units IV and VI, which discuss the TCE risk
assessment and EPA's regulatory assessment of the use of TCE in vapor
degreasing. A discussion of the environmental effects of TCE can be
found in Unit II.D.
    With respect to the costs and benefits of this proposal and the
alternatives EPA considered, as well as the impacts on small
businesses, the full analysis is presented in the economic analysis
document (Ref. 3) To the extent information was available, EPA
considered the benefits realized from risk reductions (including
monetized benefits, non-monetized quantified benefits, and qualitative
benefits), offsets to benefits from countervailing risks (e.g., risks
from chemical substitutions and alternative practices), the relative
risk for environmental justice populations and children and other
potentially exposed or susceptible subpopulations (as compared to the
general population), and the cost of regulatory requirements for the
various options. A discussion of the benefits EPA considered can be
found in Units VI.C. and VII.
    EPA considered the estimated costs to regulated entities as well as
the cost to administer and enforce the options. For example, an option
that includes use of a respirator would include inspections to evaluate
compliance with all elements of a respiratory protection program. EPA
took into account reasonably available information about the
functionality and performance efficacy of the regulatory options and
the ability to implement the use of chemical substitutes or other
alternatives (e.g., PPE). Reasonably available information included the
existence of other Federal, state, or international regulatory
requirements associated with each of the regulatory options as well as
the commercial history for the options. A discussion of the costs EPA
considered can be found in Units VI.E. and VII, along with a discussion
of the cost effectiveness of the proposal and the alternatives that EPA
considered. In addition, a discussion of the impacts on small
businesses can be found in Unit XII.C.
    With respect to the anticipated effects of this proposal on the
national economy, EPA considered the number of businesses and workers
that would be affected and the costs and benefits to those businesses
and workers. In addition, EPA considered the employment impacts of this
proposal, as discussed in the economic analysis for this proposal (Ref.
3). EPA found that the direction of change in employment is uncertain,
but the expected short term and longer term employment effects are
expected to be small.
    The benefits of TCE in vapor degreasing are discussed in Unit
VI.D., along with the availability of alternatives. The dates that the
proposed restrictions would take effect are discussed in Unit X.D., as
is the availability of alternatives to TCE vapor degreasing on those
dates.
    Finally, with respect to this proposal's effect on technological
innovation, EPA expects this action to spur innovation, not hinder it.
(Ref. 3) An impending ban on the use of TCE in vapor degreasing is
likely to increase demand for alternatives, which would be expected to
result in the development of new alternatives.

C. Regulatory Options Receiving Limited Evaluation

    As discussed previously, EPA analyzed a wide range of regulatory
options under TSCA section 6(a). One of the options EPA evaluated
involved a TSCA section 6(a)(3) requirement for warning labels or
instructions on containers of TCE or on vapor degreasing equipment.
However, EPA

reasoned that warning labels and instructions alone could not mitigate
the identified unreasonable risks presented by TCE to workers operating
vapor degreasing equipment. In making this finding, EPA considered
several factors including the fact that, in many cases, the workers
being exposed are not in a position to influence their employer's
decisions about the type of solvent or the type of degreasing equipment
that will be used, or ensure that their employer provides appropriate
PPE and an adequate respiratory protection program. EPA also considered
the analysis of relevant studies that was discussed in the prior
proposal on TCE (Ref. 33). This analysis found that even professional
users do not consistently pay attention to labels; they often do not
understand label information; and they often base a decision to follow
label information on previous experience and perceptions of risk (Ref.
33).
    EPA found that presenting information about TCE on a label would
not adequately address the identified unreasonable risks because the
nature of the information the user or owner would need to read,
understand, act upon, convey, and ensure adherence to is extremely
complex. It would be challenging to most users or owners to follow or
convey the complex product label instructions required to explain how
to reduce exposures to the extremely low levels needed to minimize the
risk from TCE. Rather than a simple message, the label would need to
explain a variety of inter-related factors, including but not limited
to the use of local exhaust ventilation, respirators and assigned
protection factor for the user and bystanders, and time periods during
pregnancy with susceptibility of the developing fetus to acute
developmental effects, as well as effects to bystanders. It is unlikely
that label language changes for this use will result in widespread,
consistent, and successful adoption of risk reduction measures by users
and owners.
    While labeling alone would not address the identified unreasonable
risks so that TCE used in vapor degreasing no longer presents such
risks, EPA recognizes that the TSCA section 6(a)(3) warnings and
instruction requirement can be an important component of an approach
that addresses identified unreasonable risks with a specific use
prohibition. EPA has included a simple downstream notification
requirement as part of this proposed rule to ensure that users would be
made aware of the ban on the use of TCE in vapor degreasing.
    In addition, early in the process, EPA identified two regulatory
options under TSCA section 6(a) that do not pertain to this action and
were therefore not evaluated for this proposed rulemaking. First, EPA
reasoned that the TSCA section 6(a)(1) regulatory option to prohibit
the manufacture (including import), processing or distribution in
commerce of TCE or limit the amount of TCE which may be manufactured
(including imports), processed or distributed in commerce is not
germane because the Agency is not proposing to ban or limit the
manufacture (including import), processing or distribution in commerce
of TCE for uses other than in vapor degreasing, aerosol degreasing or
for spot cleaning in dry cleaning facilities at this time. In addition,
EPA reasoned that the TSCA section 6(a)(6) regulatory option to
prohibit or otherwise regulate any manner or method of disposal of the
chemical is not applicable since EPA did not evaluate the risks
associated with ongoing TCE disposal.

VI. Regulatory Assessment of TCE Use in Vapor Degreasing

    This Unit describes the current use of TCE in vapor degreasing, the
unreasonable risks presented by this use, and how EPA identified which
regulatory options address those unreasonable risks so that TCE in
vapor degreasing no longer presents such unreasonable risks.

A. Description of the Current Use

    Vapor degreasing is a cleaning process that uses a solvent vapor to
remove contaminants such as grease, oils, dust, and dirt from
fabricated parts. Solvents such as TCE are boiled in a degreasing unit
to produce a hot vapor. When parts are placed into the degreaser, the
hot vapor within the unit condenses onto the parts, causing beading and
dripping. The dripping action carries the contaminants away from the
fabricated part, leaving behind a clean surface. After vapor
degreasing, the parts are suspended on a rack in order to drain the
solvent (Ref. 30). Vapor degreasing is used in a variety of
occupational settings such as metal plating, electronics assembly,
metal or composite part fabrication, and repair shops.
    Vapor degreasing may take place in batches or as part of an in-line
(i.e., continuous) system. In batch machines, each load (parts or
baskets of parts) is loaded into the machine after the previous load is
completed. With in-line systems, parts are continuously loaded into and
through the vapor degreasing equipment as well as the subsequent drying
steps.
    The five basic types of batch vapor degreasers are described in the
following paragraphs (Ref. 30):
    As the name suggests, open-top vapor degreasers are open at the top
to allow introduction of the parts to be cleaned. Heating elements at
the bottom of the cleaner heat the liquid solvent to above its boiling
point. Solvent vapor rises in the machine to the height of chilled
condensing coils on the inside walls of the cleaner. The condensing
coils cool the vapor, causing it to condense and return to the bottom
of the cleaner. Cleaning occurs in the vapor zone above the liquid
solvent and below the condensing coils, as the hot vapor solvent
condenses on the cooler work surface. The workload or a parts basket is
lowered into the heated vapor zone with a mechanical hoist. While the
condensing coils reduce the amount of solvent that escapes the vapor
zone, they do not eliminate emissions, and throughout the degreasing
process, significant vapor emissions of the solvent can occur. These
vapor emissions are hazardous to workers operating the machine, as well
as nearby workers. In addition, replacing solvent lost to emissions can
be costly. In assessing the use of TCE in vapor degreasers, the TCE
risk assessment focused on the use of open top vapor degreasing
systems.
    Vapor emissions of solvent can be reduced by enclosing the vapor
degreasing machine. Open top vapor degreasing systems with enclosures
operate in the same manner as standard open top vapor degreasing
systems, except that the machine is enclosed on all sides during
degreasing. The enclosure is opened and closed when adding or removing
parts, and solvent is exposed to the air when the cover is open. Nearly
all open top vapor degreasing systems regulated by the NESHAP have a
cover because that is a more common compliance strategy than complying
with the overall emission limit. A variety of additional controls may
be needed to comply with the NESHAP, including two-part covers,
extended freeboard (the area above the vapor zone), freeboard
refrigeration devices, and holding cleaned parts in the freeboard to
allow draining. Enclosed vapor degreasing systems may be vented
directly to the atmosphere or first vented to an external carbon filter
and then to the atmosphere.
    Solvent emissions can be further reduced by using a sealed, closed-
loop degreasing system. In airtight closed-loop systems, parts are
placed into a basket, which is then placed into an airtight work
chamber. The door is closed and solvent vapors are sprayed

onto the parts. When cleaning is complete, vapors are exhausted from
the work chamber and circulated over a cooling coil to condense and
recover the solvent. The parts are dried by forced hot air. Air is
circulated through the chamber and residual solvent vapors are captured
by carbon adsorption. The door is opened when the residual solvent
vapor concentration has reached a specified level.
    A refinement of the airtight closed-loop degreasing system is the
airless degreasing system. An airless system removes air at some point
during the degreasing process. Typically, this takes the form of
drawing vacuum, but some machines purge the air with nitrogen. In
airless degreasing systems with vacuum drying, a vacuum is generated,
typically below 5 torr, which dries the parts. A vapor recovery system
recovers the solvent.
    The greatest solvent emission reductions are achieved with the
airless vacuum-to-vacuum degreasing system. These systems are referred
to as airless because the entire cycle is operated under vacuum.
Typically, parts are placed into the chamber, the chamber sealed, and
then vacuum drawn within the chamber. The parts are then sprayed with
hot solvent vapor, which raises the pressure in the chamber. The parts
are dried by again drawing vacuum in the chamber. Solvent vapors are
recovered through compression and cooling. An air purge then removes
residual vapors which can be routed to an optional carbon adsorber and
then out a vent. Finally, air is introduced to return the chamber to
atmospheric pressure so that the chamber can be opened. These systems
have the added benefit of generating vapor at a much lower temperature
than open-top degreasing systems because the boiling point of TCE is
lower at the lower pressure of these systems.
    In contrast to batch degreasers, in-line vapor degreasing systems
use an automated parts handling system, often a conveyor, to
automatically provide a continuous supply of parts to be cleaned (Ref.
30). Conveyorized vapor degreasing systems are usually fully enclosed
except for the conveyor inlet and outlet portals. Conveyorized
degreasers are likely used in the same applications as batch vapor
degreasers, except that they would be used in larger operations, where
the number of parts being cleaned is large enough to warrant the use of
a conveyorized system. Conveyorized degreasers use different methods
for transporting the parts through the cleaning zone. For example,
monorail degreasers use a straight-line conveyor to transport parts
into and out of the cleaning zone; these systems are typically used
when parts are already being transported through manufacturing areas by
a conveyor. Cross-rod degreasers use two parallel chains connected by a
rod to support the parts, which are typically loaded manually into
perforated baskets or cylinders. Ferris wheel degreasing systems,
generally the smallest of the conveyorized degreasers, rotate manually-
loaded baskets or cylinders of parts vertically through the cleaning
zone and back out. Belt degreasers are used for simple and rapid
loading and unloading of parts; the parts are loaded onto a mesh
conveyor belt that transports them through the cleaning zone and out
the other side.
    There are also continuous web cleaning machines (Ref. 30). These
in-line degreasers differ from typical conveyorized degreasers in that
they are specifically designed for cleaning parts that are coiled or on
spools such as films, wires, metal strips, and metal sheets. In
continuous web degreasers, parts are uncoiled and loaded onto rollers
that transport the parts through the cleaning and drying zones at
speeds typically greater than 11 feet per minute. The parts are then
recoiled or cut after exiting the machine.

B. Analysis of Regulatory Options

    In this unit, EPA explains how it evaluated whether the regulatory
options considered would address the unreasonable risks presented by
the current use so that TCE in vapor degreasing no longer presents such
unreasonable risks. First, EPA characterizes the unreasonable risks
associated with the current use of TCE in vapor degreasers. Then, the
Agency describes its initial analysis of which regulatory options have
the potential to reach the protective non-cancer and cancer benchmarks.
The levels of acute and chronic exposures estimated to present low risk
for non-cancer effects also result in low risk for cancer. Lastly, this
unit evaluates how well those regulatory options would address the
identified unreasonable risks in practice.
    1. Risks associated with the current use. a. General impacts. The
TCE risk assessment identified cancer and non[hyphen]cancer risks from
acute and chronic exposure for workers operating vapor degreasers and
for occupational bystanders, nearby workers who have the potential to
be exposed to TCE but are not directly involved with degreasing
operations (Ref. 2). Because the TCE risk assessment focused on open
top vapor degreasing systems, EPA performed supplemental analysis
consistent with the methodology used in the risk assessment for closed-
loop, conveyorized, and continuous web degreasers and identified cancer
and non[hyphen]cancer risks from acute and chronic exposure for each of
the scenarios (Ref. 30). EPA estimates that there are approximately
2,600 to 6,000 open top vapor degreasing systems currently using TCE,
120 closed-loop systems currently using TCE, and 150 in-line (either
conveyorized or continuous web) systems currently using TCE, with an
estimated 17 workers and occupational bystanders per machine (Ref. 3).
This means that there are an estimated 40,800 to 102,000 persons
exposed to TCE from open top vapor degreasing systems, 2,040 persons
exposed to TCE from closed-loop systems, and 2,550 persons exposed to
TCE from in-line systems.
    b. Impacts on minority and low income populations. There is no
known disproportionate representation of minority or low income
populations in these occupations.
    c. Impacts on children. EPA has concerns for effects on the
developing fetus from acute and chronic worker and occupational
bystander exposures to TCE used in vapor degreasers. The risk estimates
are focused on pregnant women because one of the most sensitive health
effects associated with TCE exposure from vapor degreasing is adverse
effects on the developing fetus. The potential risk due to exposure
during pregnancy is significant. Approximately half of all pregnancies
are unintended. If a pregnancy is not planned before conception, a
woman may not be in optimal health for childbearing (Ref. 34). More
specifically, in this case, a woman who is not planning a pregnancy may
not take steps to avoid exposure to TCE in vapor degreasing. EPA
estimates that there are over 1,000 pregnant women exposed to TCE as a
result of vapor degreasers.
    d. Specific vapor degreaser exposure information. In the
supplemental analysis (Ref. 30), EPA estimated baseline exposures for
all batch vapor degreasing machines, regardless of facility size, and
for in-line vapor degreasing machines (both conveyorized and continuous
web). Baseline exposures for in-line machines were not specifically
calculated in the TCE risk assessment. For the supplemental analysis,
estimating the baseline exposures involved using a near-field/far-field
modeling approach to estimate airborne concentrations of TCE and Monte
Carlo simulation to establish the range and likelihood of exposures.
The near-field/far-field model estimates airborne concentrations in a
near field (a

zone close to the source of exposure) and a far field (a zone farther
from the source of exposure but within the occupational building).
Controls required by the 2007 NESHAP were accounted for in the
estimations. (Ref. 30) EPA used these estimated airborne concentrations
to estimate 8-hour time weighted average (TWA) exposures for workers
(i.e., in the near field) and occupational bystanders (i.e., in the far
field). Details of the modeling and estimation method for calculating
exposure levels during vapor degreasing are available in the
supplemental analysis document (Ref. 30). This analysis is based on the
methodology used in the peer reviewed TCE risk assessment (Ref. 2).
Prior to promulgation of the final rule, EPA will peer review the
``supplemental Occupational Exposure and Risk Reduction Technical
Report in Support of Risk Management Options for Trichloroethylene
(TCE) Use in Vapor Degreasing'' (Ref. 30).
    The estimated 8-hour TWA exposure levels for open top vapor
degreasing systems ranged from 2.74 ppm to 491.36 ppm for workers, with
the 50th percentile at 55.16 ppm and the 99th percentile at 190.17 ppm.
For occupational bystanders, the exposure levels ranged from 0.33 ppm
to 440.61 ppm, with the 50th percentile at 20.45 ppm and the 99th
percentile at 144.93 ppm. The estimated 8-hour TWA exposure levels for
conveyorized degreasers were even higher, ranging from 5.14 ppm to
32,722 ppm for workers, with the 50th percentile and 99th percentile
being 180.74 ppm and 1162.6 ppm, respectively. For bystanders, the
levels ranged from 0.63 ppm to 29,410 ppm, with the 50th percentile and
99th percentile being 80.93 ppm and 745.11 ppm, respectively. The
estimated 8-hour TWA exposure levels for continuous web degreasers were
lower overall than for open top vapor degreasing systems or
conveyorized degreasers. These estimates ranged from 4.18 ppm to 50.61
ppm for workers, with the 50th percentile and 99th percentile being
8.18 ppm and 22.42 ppm, respectively. For bystanders, the levels ranged
from 0.52 ppm to 45.49 ppm, with the 50th percentile and 99th
percentile being 3.70 ppm and 17.49 ppm, respectively.
    As part of this supplemental analysis, EPA also evaluated the
exposure reductions that would result from switching from an open top
vapor degreasing system to a closed-loop vapor degreasing system. The
data available on TCE emissions from closed-loop systems was not
sufficient to enable EPA to distinguish between the three types of
closed-loop systems (airtight, airless, and airless vacuum-to-vacuum)
with respect to employee exposures. As a result, for the purpose of
assessing exposure, EPA assumed that all of the closed-loop systems
achieve a 98% reduction in exposure compared to open top vapor
degreasing systems (Ref. 30). This assumption leads to exposure
estimates of 0.05 ppm to 9.8 ppm for workers.
    However, the assumption of a 98% reduction in exposures compared to
open top vapor degreasing systems may be an overestimate for airtight
systems, and an underestimate for airless vacuum-to-vacuum systems. EPA
requests information and data on TCE emissions from all vapor
degreasing systems, particularly information and data that would enable
EPA to better distinguish between the different types of closed-loop
systems.
    The SBAR Panel convened in support of this action heard from
several SERs who disagreed with EPA's exposure estimates. These SERs
indicated that fewer employees were involved in the degreasing
operation, or that the machines were operated for fewer hours per day
than EPA estimated. However, another SER stated that his degreasing
machines run ten hours a day during the week and six hours on
Saturdays, which exceeds EPA's estimate. In addition, most SERs thought
that EPA's estimated TWAs were too high, and EPA received some
monitoring data indicating lower exposures, but several SERs stated
that they complied with the recommended exposure limit of the American
Conference of Governmental Industrial Hygienists (ACGIH) of 10 ppm,
which is within the exposure ranges estimated by EPA. However, EPA
specifically requests exposure data, especially data involving employee
exposure monitoring.
    e. Specific risks for TCE use in vapor degreasers. Inhalation risks
were estimated for all acute exposure scenarios and risks were
identified for all types of machines, regardless of the type of
exposure (typical vs. reasonable worst case scenario). For acute
exposures associated with open top vapor degreasing systems, the MOE is
0.00006 for fetal heart malformations. This equates to exposures that
are many times greater than the benchmark MOE of 10. The MOE for fetal
heart malformations from acute exposures associated with conveyorized
systems is 0.00001, while for continuous web systems, the MOE is
0.0005. Even for acute exposures with closed-loop systems, which we
assume reduce TCE emissions as much as 98% from open top vapor
degreasing systems, the MOE for fetal heart malformations is 0.003. The
MOEs for every vapor degreasing scenario are below the benchmark MOE.
Based on this assessment, EPA's proposed determination is that acute
TCE exposures from vapor degreasing present unreasonable risks.
    Chronic exposures from TCE use in vapor degreasing also present
risks. For non-cancer effects, the most sensitive of which are
developmental, the benchmark MOE is also 10. For chronic exposures
associated with open top vapor degreasing systems, conveyorized
systems, continuous web systems, and closed-loop systems, the MOEs are
0.00008, 0.00001, 0.00007, and 0.004, respectively. With respect to
cancer, the risk posed to workers ranges from 5.16 x 10-1
for open top vapor degreasing systems to 1 x 10-2 for
closed-loop systems, exceeding common cancer benchmarks of
10-6 to 10-4 (Refs. 2, 30). Therefore, EPA's
proposed determination is that chronic TCE exposures due to vapor
degreasing also present unreasonable risks.
    The SBAR Panel convened in support of this action heard from
several SERs who expressed concerns about the underlying TCE risk
assessment. Many of the concerns expressed by these SERs were already
expressed in the public comments and the peer review comments on the
risk assessment. The Summary of External Peer Review and Public
Comments and Disposition document explains how EPA responded to the
comments received (Ref. 35).
    2. Initial analysis of potential regulatory options. Having
identified unreasonable risks from the use of TCE in vapor degreasing,
EPA evaluated whether regulatory options under TSCA section 6(a) could
reach the risk (non-cancer and cancer) benchmarks.
    EPA assessed a number of exposure scenarios associated with risk
reduction options in order to find variations in TCE exposure from
vapor degreasing, including: Reducing the amount of TCE in the
degreasing formulation, with concentrations varying from 5% to 95% by
weight in the product, engineering controls, equipment substitution,
and use of PPE. EPA also assessed combinations of these options.
    For the engineering controls risk reduction option exposure
scenarios, EPA evaluated using local exhaust ventilation to improve
ventilation near the vapor degreaser, with an assumed 90% reduction in
exposure over baseline levels. The equipment substitution risk
reduction option was only evaluated with respect to open top vapor
degreasing systems, the evaluation assumed substitution of a closed-
loop system for the open top

vapor degreasing system. EPA did not identify any equipment
substitution options for either conveyorized or continuous web systems;
it is likely that a closed-loop system, being a batch-process system,
would not meet the specialized production requirements of facilities
currently using conveyorized or continuous web systems. EPA requests
comment, information, and data on potential equipment substitution
options for these systems, including both emissions and cost
information. The PPE risk reduction option exposure scenarios evaluated
workers and occupational bystanders wearing respirators with an
assigned protection factor (APF) varying from 10 to 10,000.
Additionally, EPA evaluated various combinations of these options,
including PPE with each of the other three options and reducing the
amount of TCE in the solvent solution with each of the other three
options. The way that closed-loop systems operate may render local
exhaust ventilation redundant, because ventilation is being done as
part of the closed system, so EPA did not evaluate local exhaust
ventilation and equipment substitution together. EPA requests comment
on the accuracy of EPA's assumption that these control options are
mutually exclusive.
    EPA has estimated that, in order to avoid cancer and non-cancer
unreasonable risks, the 8-hour TWA exposure should be approximately 1
ppb (Ref. 36). However, EPA's inhalation exposure level estimates for
all types of vapor degreasing machines exceed that figure by several
orders of magnitude.
    Of the control options evaluated by EPA in its supplemental
analysis (Ref. 30), which did not include a ban on the use of TCE in
vapor degreasing, the only control options that achieved the necessary
exposure reductions for workers operating the degreaser involved PPE in
addition to other measures. Even switching from an open top vapor
degreasing system to a closed-loop system did not achieve the necessary
reductions without the addition of PPE with an APF of 10,000. For that
control option, equipment substitution plus PPE, EPA estimated that
worker exposure levels would be 0.4 ppb. Other combinations of control
options, such as reducing the amount of TCE in the solvent solution and
PPE with an APF of 10,000, or reducing the amount of TCE in the solvent
solution and engineering controls and PPE, achieved exposure reductions
of approximately the same magnitude. However, EPA found that these
combinations are unlikely to be practical for users because the
exposure reductions needed would only be achieved by a reduction in the
concentration of TCE in the degreasing solution to 5%. At 5% TCE, the
effectiveness of the solution would be greatly reduced. Additional
exposure level estimates for various scenarios are available in the
supplemental analysis document, which also documents options that did
not meet the risk benchmarks and which do not, for purposes of this
proposal, address the identified unreasonable risks (Ref. 30).
    3. Assessment of whether regulatory options address the identified
unreasonable risks to the extent necessary so that TCE no longer
presents such unreasonable risks. After excluding the unrealistic
options involving reductions in the amount of TCE in the solvent
solution, only two options were left that had the potential to address
the identified unreasonable risks. These options were: (a) Prohibiting
under TSCA section 6(a)(2) the manufacturing (including import),
processing, and distribution in commerce of TCE for use in vapor
degreasing, prohibiting the commercial use of TCE in vapor degreasing
under TSCA section 6(a)(5), and requiring downstream notification under
TSCA section 6(a)(3) when distributing TCE; and (b) prohibiting under
TSCA section 6(a)(2) the manufacturing (including import), processing,
and distribution in commerce of TCE for use in vapor degreasing except
in closed-loop vapor degreasing machines, prohibiting under TSCA
section 6(a)(5) the commercial use of TCE in vapor degreasing except in
closed-loop vapor degreasing machines, requiring downstream
notification under TSCA section 6(a)(3) when distributing TCE, and
requiring, under TSCA section 6(a)(5), appropriate PPE (or an exposure
limit alternative) for both workers operating closed-loop vapor
degreasing machines containing TCE and for occupational bystanders.
    a. Proposed approach to prohibit manufacturing (including import),
processing, distribution in commerce, and use of TCE for vapor
degreasing and require downstream notification. As noted previously,
the proposed regulatory approach is to prohibit the manufacturing
(including import), processing, and distribution in commerce of TCE for
vapor degreasing under TSCA section 6(a)(2), prohibit the commercial
use of TCE in vapor degreasing under TSCA section 6(a)(5), and require
manufacturers, processors, and distributors, except for retailers, to
provide downstream notification, e.g., via a Safety Data Sheet (SDS),
of the prohibition under TSCA section 6(a)(3).
    As discussed in Unit IV, the baseline risk for exposure to workers
and occupational bystanders for vapor degreasing does not achieve the
non-cancer MOE benchmarks for all non-cancer effects (e.g.,
developmental effects, kidney toxicity, and immunotoxicity) or the
common cancer benchmarks. Under this proposed approach, exposures to
TCE from use in vapor degreasing would be completely eliminated. As a
result, both non-cancer and cancer risks from this use of TCE would be
eliminated.
    The proposed approach would ensure that employees are no longer at
risk from TCE exposure associated with vapor degreasing. Prohibiting
the manufacturing (including import), processing and distribution in
commerce of TCE for use in vapor degreasing would minimize the
availability of TCE for vapor degreasing. The downstream notification
of these restrictions ensures that processors, distributors, and other
purchasers are aware of the manufacturing (including import),
processing, distribution in commerce and use restrictions for TCE in
vapor degreasing, and helps to ensure that the rule is effectively
implemented by discouraging off-label use of TCE manufactured for other
uses. Downstream notification is important because EPA is not proposing
to prohibit manufacturing, processing and all uses of TCE, just those
activities associated with vapor degreasing. This integrated supply
chain approach is necessary to address the identified unreasonable
risks presented by the use of TCE in vapor degreasing. In addition, the
proposed approach would provide staggered compliance dates for
implementing the prohibition on manufacturing (including import),
processing, distribution in commerce, and commercial use in order to
avoid undue impacts on the businesses involved.
    b. Variation of the proposed approach that would allow the use of
TCE in closed-loop vapor degreasing systems and require under TSCA
section 6(a)(5) the use of personal protective equipment in vapor
degreasing operations in which TCE is used. Another regulatory option
that EPA considered was to allow the use of TCE in closed-loop vapor
degreasing systems and require respiratory protection equipment for
workers operating the equipment in the form of a full face piece self-
contained breathing apparatus (SCBA) in pressure demand mode or other
positive pressure mode with an APF of 10,000 with an alternative to the
specified APF respirator of an air exposure limit. EPA's analysis found

that use of a SCBA with an APF of 10,000 for workers operating closed-
loop vapor degreasing systems that contain TCE could control TCE air
concentration to levels that ensure that TCE no longer presents the
identified unreasonable risks. Depending on air concentrations and
proximity to the vapor degreasing equipment, other employees in the
area would also need to wear respiratory protection equipment.
    Although respirators could reduce exposures to levels that are
protective of non-cancer and cancer risks, there are many documented
limitations to successful implementation of respirators with an APF of
10,000. Not all workers can wear respirators. Individuals with impaired
lung function, due to asthma, emphysema, or chronic obstructive
pulmonary disease, for example, may be physically unable to wear a
respirator. Determination of adequate fit and annual fit testing is
required for a tight fitting full-facepiece respirator to provide the
required protection. Also, difficulties associated with selection, fit,
and use often render them ineffective in actual application, preventing
the assurance of consistent and reliable protection, regardless of the
assigned capabilities of the respirator. Individuals who cannot get a
good facepiece fit, including those individuals whose beards or
sideburns interfere with the facepiece seal, would be unable to wear
tight fitting respirators. In addition, respirators may also present
communication problems and vision problems, increase worker fatigue,
and reduce work efficiency (Ref. 37). According to OSHA, ``improperly
selected respirators may afford no protection at all (for example, use
of a dust mask against airborne vapors), may be so uncomfortable as to
be intolerable to the wearer, or may hinder vision, communication,
hearing, or movement and thus pose a risk to the wearer's safety or
health.'' (Ref. 37, at 1189-1190). Nonetheless, it is sometimes
necessary to use respiratory protection to control exposure. The OSHA
respiratory protection standard requires employers to establish and
implement a respiratory protection program to protect their respirator-
wearing employees (Ref. 38). This OSHA standard contains a number of
implementation requirements, e.g., for program administration;
worksite-specific procedures; respirator selection; employee training;
fit testing; medical evaluation; respirator use; respirator cleaning,
maintenance, and repair; and other provisions that would be difficult
to fully implement in some small business settings where they are not
already using respirators.
    In addition, OSHA adopted a hierarchy of controls established by
the industrial hygiene community used to protect employees from
hazardous airborne contaminants, such as TCE (see, e.g., 29 CFR
1910.134(a)(1), 29 CFR 1910.1000(e), and OSHA's substance specific
standards in 29 CFR 1910 subpart Z). According to the hierarchy,
substitution of less toxic substances, engineering controls,
administrative controls, and work practice controls are the preferred
method of compliance for protecting employees from airborne
contaminants and are to be implemented first, before respiratory
protection is used. OSHA permits respirators to be used where
engineering controls are not feasible or during an interim period while
such controls are being implemented.
    Under this approach, a company could choose to use a closed-loop
system coupled with an air exposure limit. In order to reach the health
benchmarks, the air exposure limit would have to be 1 ppb as an 8-hour
TWA. Based on EPA's analysis, the only way to achieve an air exposure
limit of 1 ppb is with a combination of a closed-loop vapor degreaser
and a respirator with an APF of 10,000. However, as previously
discussed, EPA acknowledges that available data is limited,
particularly with respect to the different types of closed-loop vapor
degreasers. It is possible that the more sophisticated airless vacuum-
to-vacuum closed-loop systems have lower emissions than EPA estimated,
and, therefore, respiratory protection with an APF of 10,000 may not be
necessary for operators. As part of this approach, EPA believes it
would be necessary to establish employee exposure monitoring
requirements to ensure that employee exposures are measured accurately
and that employees are not exposed to the identified unreasonable risks
associated with TCE use in vapor degreasing. EPA would require upfront
monitoring representative of each exposed employee's exposures and
would model the requirements on comparable OSHA requirements as well as
on the New Chemical Exposure Limit (NCEL) requirements that EPA has
long used in addressing employee exposure to chemicals undergoing
review under TSCA section 5 (Refs. 38-39). The requirements would
specify how and when sampling must be performed and how the samples
would have to be analyzed.
    EPA is not proposing this option because substitutes for TCE are
commercially available and implementation of a respiratory protection
program is likely to be difficult for many vapor degreasing facilities.
In addition, EPA's economic analysis indicates that this option is more
expensive than switching to a different solvent or cleaning system.
However, EPA requests comment, information, and data on the utility and
feasibility of this option and whether, if it were adopted, it should
be implemented by specifying the vapor degreasing technology and either
requiring specific PPE or compliance with an air exposure limit. If EPA
were to specify both the vapor degreasing technology and the required
PPE with the alternative air exposure limit in the final rule, EPA
would require the vapor degreasing system to be an airless vacuum-to-
vacuum closed-loop system and the PPE to have an APF of 10,000 or
otherwise meet the air exposure limit of 1 ppb as an 8-hour TWA. As
previously discussed, EPA's assessment of worker exposure from closed-
loop systems relies on an assumption that emissions from each closed-
loop system are 98% less than the emissions from an open top vapor
degreasing system. EPA is requesting information on whether releases
from the use of TCE in an airless vacuum-to-vacuum closed-loop system
would result in air levels that are at or below the air exposure limit
of 1 ppb. To the extent that EPA receives information that indicates
that this is the case, EPA would consider finalizing this rule to
exclude airless vacuum-to-vacuum closed-loop systems. In contrast, this
assumption of a 98% reduction may be overly generous for the most basic
of the closed-loop systems, and operators of such systems, even when
wearing PPE with an APF of 10,000, would continue to be exposed to the
identified unreasonable risks. Under the optional approach, companies
choosing to keep using TCE would have to comply with all of OSHA's
requirements for respiratory protection programs, including fit-testing
and medical monitoring.

C. Adverse Health Effects and Related Impacts That Would Be Prevented
by the Proposed Option

    The proposed option would prevent exposure to TCE from vapor
degreasing and thus would prevent the risks of adverse effects and
associated impacts. As discussed in Unit IV., TCE exposure is
associated with a wide array of adverse health effects. These health
effects include those resulting from developmental toxicity (e.g.,
cardiac malformations, developmental immunotoxicity, developmental
neurotoxicity, fetal death), toxicity to

the kidney (kidney damage and kidney cancer), immunotoxicity (systemic
autoimmune diseases such as scleroderma) and severe hypersensitivity
skin disorder, non-Hodgkin's lymphoma, endocrine and reproductive
effects (e.g., decreased libido and potency), neurotoxicity (e.g.,
trigeminal neuralgia), and toxicity to the liver (impaired functioning
and liver cancer) (Ref. 2). These health effects associated with
exposure to TCE are serious and can have impacts throughout a lifetime.
The following is a discussion of the impacts of significant acute,
chronic non-cancer, and cancer effects associated with TCE exposure
during vapor degreasing, including the severity of the effect, the
manifestation of the effect, and how the effect impacts a person during
their lifetime.
    1. Developmental effects. The TCE risk assessment (and EPA's 2011
IRIS Assessment) identified developmental effects as the critical
effect of greatest concern for both acute and chronic non-cancer risks.
There are increased health risks for developmental effects to the
estimated 454 to 1,066 pregnant women exposed to TCE during the use of
vapor degreasers (Ref. 3). Specifically, these assessments identified
fetal cardiac malformations in the offspring of mothers exposed to TCE
during gestation as the critical effect. Although fetal cardiac defects
are the effect of greatest concern and are the focus of the discussion
in this Unit, TCE exposures can result in other adverse developmental
outcomes, including prenatal (e.g., spontaneous abortion and perinatal
death, decreased birth weight, and congenital malformations) and
postnatal (e.g., reduced growth, decreased survival, developmental
neurotoxicity, developmental immunotoxicity, and childhood cancers)
effects. TCE exposure during development results in qualitatively
different immunotoxic effects than when exposure occurs during
adulthood. TCE exposure during development can influence the
development of the immune system and result in impairment of the immune
system's ability to respond to infection, whereas TCE exposures during
adulthood result in a more pronounced immune effect related to
autoimmune responses.
    Cardiac defects, which can result from low-level exposure to TCE,
affect the structural development of a baby's heart and how it works.
The defects impact how blood flows through the heart and out to the
rest of the body. The impact can be mild (such as a small hole in the
heart) or severe (such as missing or poorly formed septal wall and
valves of the heart). While diagnosis for some cardiac defects can
occur during pregnancy, for other cardiac defects, detection may not
occur until after birth or later in life, during childhood or
adulthood. These cardiac defects can be occult or life- threatening
with the most severe cases causing early mortality and morbidity. While
the incidences in the following paragraphs reflect adverse health
outcomes beyond just exposure to TCE, the general population numbers
provide a context for understanding the impact of the adverse health
effects TCE can cause.
    Nearly 1% or about 40,000 births per year in the United States are
affected by cardiac defects (Ref. 40). About 25% of those infants with
a cardiac defect have a critical defect. Infants with critical cardiac
defects generally need surgery or other procedures in their first year
of life. Some estimates put the total number of individuals (infants,
children, adolescents, and adults) living with cardiac defects at 2
million (Ref. 40). Cardiac defects can be caused by genetics,
environmental exposure, or an unknown cause.
    Infant deaths resulting from cardiac defects often occur during the
neonatal period. One study indicated that cardiac defects accounted for
4.2% of all neonatal deaths. Of infants born with a non-critical
cardiac defect, 97% are expected to survive to the age of one, with 95%
expected to survive to 18 years of age. Of infants born with a critical
cardiac defect, 75% are expected to survive to one year of age, with
69% expected to survive to 18 years of age (Ref. 41). A child with a
cardiac defect is 50% more likely to receive special education services
compared to a child without birth defects (Ref. 40).
    Treatments for cardiac defects vary. Some affected infants and
children might need one or more surgeries to repair the heart or blood
vessels. In other instances, a heart defect cannot be fully repaired,
although treatments have advanced such that infants are living longer
and healthier lives. Many children are living into adulthood and lead
independent lives with little or no difficulty. Others, however, may
develop disability over time, making it difficult to predict and
quantify impacts.
    Even though a person's heart defect may be repaired, for many
people this is not a cure. They can still develop other health problems
over time, depending on their specific heart defect, the number of
heart defects they have, and the severity of their heart defect. For
example, some related health problems that might develop include
irregular heart beat (arrhythmias), increased risk of infection in the
heart muscle (infective endocarditis), or weakness in the heart
(cardiomyopathy). In order to stay healthy, a person needs regular
checkups with a cardiologist. They also might need further operations
after initial childhood surgeries (Ref. 40).
    Depending upon the severity of the defect, the costs for surgeries,
hospital stays, and doctor's appointments to address a baby's cardiac
defect can be significant. The costs for the defects may also continue
throughout a person's lifetime. In 2004, hospital costs in the United
States for individuals with a cardiac defect were approximately $1.4
billion (Ref. 40).
    Beyond the monetary cost, the emotional and mental toll on parents
who discover that their child has a heart defect while in utero or
after birth will be high (Ref. 41). They may experience anxiety and
worry over whether their child will have a normal life of playing with
friends and participating in sports and other physical activities, or
whether their child may be more susceptible to illness and be limited
in the type of work and experiences they can have. In addition, parents
can be expected to experience concerns over potential unknown medical
costs that may be looming in the future, lifestyle changes, and being
unable to return to work in order to care for their child.
    The emotional and mental toll on a person throughout childhood and
into adolescence with a heart defect also should be considered (Ref.
41). Cardiac patients who are children may feel excluded from
activities and feel limited in making friends if they have to miss
school due to additional surgeries, or may not be able to fully
participate in sports or other physical exercise. Children may feel
self-conscious of the scars left by multiple surgeries. This, in turn,
adds emotional and mental stress to the parents as they observe their
child's struggles.
    As a person with a heart defect enters adulthood, the emotional or
mental toll of a cardiac defect may continue or in other instances the
problem may only surface as an adult. If a cardiac defect impacts a
person's ability to enter certain careers, this could take a monetary
as well as emotional toll on that person and on their parents or
families who may need to provide some form of financial support. The
monetary, emotional, and mental costs of heart defects can be
considerable, and even though neither the precise reduction in
individual risk of developing a cardiac defect from reducing TCE
exposure or the total

number of cases avoided can be estimated, their impact should be
considered.
    2. Kidney toxicity. a. Non-cancer chronic effects. The TCE risk
assessment identified kidney toxicity as a significant concern from TCE
exposure with the risk from this non-cancer effect being from chronic
exposure. There are increased health risks for kidney toxicity to the
approximately 2,670 to 6,270 workers and 42,720 to 100,320 occupational
bystanders in facilities that use TCE for vapor degreasing, where
exposure to TCE is a result of vapor degreasing operations (Ref. 3).
    Exposure to TCE can lead to changes in the proximate tubules of the
kidney. This damage may result in signs and symptoms of acute kidney
failure that include; decreased urine output, although occasionally
urine output remains normal; fluid retention, causing swelling in the
legs, ankles or feet; drowsiness; shortness of breath, fatigue,
confusion, nausea, seizures or coma in severe cases; and chest pain or
pressure. Sometimes acute kidney failure causes no signs or symptoms
and is detected through lab tests done for another reason.
    Kidney toxicity means the kidney(s) has suffered damage that can
result in a person being unable to rid their body of excess urine and
wastes. In extreme cases where the kidney(s) is impaired over a long
period of time, the kidney(s) could be damaged to the point that it no
longer functions. When a kidney(s) no longer functions, a person needs
dialysis and ideally a kidney transplant. In some cases, a non-
functioning kidney(s) can result in death. Kidney dialysis and kidney
transplantation are expensive and incur long-term health costs if
kidney function fails (Ref. 42).
    Approximately 31 million people, or 10% of the adult population, in
the United States have chronic kidney disease. In the United States, it
is the ninth leading cause of death. About 93% of chronic kidney
disease is from known causes, including 44% from diabetes and 28.4%
from high blood pressure. Unknown or missing causes account for about
6.5% of cases, or about 2 million people (Ref. 43).
    The monetary cost of kidney toxicity varies depending on the
severity of the damage to the kidney. In less severe cases, doctor
visits may be limited and hospital stays unnecessary. In more severe
cases, a person may need serious medical interventions, such as
dialysis or a kidney transplant if a donor is available, which can
result in high medical expenses due to numerous hospital and doctor
visits for regular dialysis and surgery if a transplant occurs. The
costs for hemodialysis, as charged by hospitals, can be upwards of
$100,000 per month (Ref. 44).
    Depending on the severity of the kidney damage, kidney disease can
impact a person's ability to work and live a normal life, which in turn
takes a mental and emotional toll on the patient. In less severe cases,
the impact on a person's quality of life may be limited, while in
instances where kidney damage is severe, a person's quality of life and
ability to work would be affected. While neither the precise reduction
in individual risk of developing kidney toxicity from reducing TCE
exposure or the total number of cases avoided can be estimated, these
costs must still be considered because they can significantly impact
those exposed to TCE.
    b. Cancer effects. Chronic exposure to TCE can also lead to kidney
cancer. The estimated value of the annualized benefit is $12 million to
$108 million at 3% and $6 million to $57 million at 7% over 20 years.
Kidney cancer rarely shows signs or symptoms in its early stages. As
kidney cancer progresses, the cancer may grow beyond the kidney,
spreading to lymph nodes or distant sites like the liver, lung or
bladder, increasing the impacts on a person and the costs to treat it.
This metastasis is highly correlated with fatal outcomes. Impacts of
kidney cancer that are not monetized include the emotional,
psychological and treatment impacts of the cancer on the well-being of
the person.
    3. Immunotoxicity. a. Non-cancer chronic effects. The TCE risk
assessment identified immunotoxicity as a chronic non-cancer effect
that is associated with TCE exposure. There are increased health risks
for immunotoxicity to the approximately 2,670 to 6,270 workers and
42,720 to 100,320 bystanders exposed to TCE as a result of vapor
degreasing operations (Ref. 3).
    Human studies have demonstrated that TCE exposed workers can suffer
from systemic autoimmune diseases (e.g., scleroderma) and severe
hypersensitivity skin disorders. Scleroderma is a chronic connective
tissue disease with autoimmune origins. The annual incidence is
estimated to be 10 to 20 cases per 1 million persons (Ref. 45), and the
prevalence is four to 253 cases per 1 million persons (Ref. 46). About
300,000 Americans are estimated to have scleroderma. About one third of
those people have the systemic form of scleroderma. Since scleroderma
presents with symptoms similar to other autoimmune diseases, diagnosis
is difficult. There may be many misdiagnosed or undiagnosed cases (Ref.
46).
    Localized scleroderma is more common in children, whereas systemic
scleroderma is more common in adults. Overall, female patients
outnumber male patients about 4-to-1. Factors other than a person's
gender, such as race and ethnic background, may influence the risk of
getting scleroderma, the age of onset, and the pattern or severity of
internal organ involvement. The reasons for this susceptibility are not
clear. Although scleroderma is not directly inherited, some scientists
believe there is a slight predisposition to it in families with a
history of rheumatic diseases (Ref. 46).
    The symptoms of scleroderma vary greatly from person to person with
the effects ranging from very mild to life threatening. If not properly
treated, a mild case can become much more serious. Relatively mild
symptoms are localized scleroderma, which results in hardened waxy
patches on the skin of varying sizes, shapes and color. The more life
threatening symptoms are from systemic scleroderma, which can involve
the skin, esophagus, gastrointestinal tract (stomach and bowels),
lungs, kidneys, heart and other internal organs. It can also affect
blood vessels, muscles and joints. The tissues of involved organs
become hard and fibrous, causing them to function less efficiently.
    Severe hypersensitivity skin disorders include exfoliative
dermatitis, mucous membrane erosions, eosinophilia, and hepatitis.
Exfoliative dermatitis is a scaly dermatitis involving most, if not
all, of the skin. Eosinophilia, on the other hand, is a chronic
disorder resulting from excessive production of a particular type of
white blood cells. If diagnosed and treated early, a person can lead a
relatively normal life (Ref. 45).
    The monetary costs for treating these various immunotoxicity
disorders will vary depending upon whether the symptoms lead to early
diagnosis and this early diagnosis can then influence whether symptoms
progress to mild or life-threatening outcomes. For mild symptoms,
doctors' visits and outpatient treatment could be sufficient, while
more severe immunotoxicity disorders, may require hospital visits.
Treatments for these conditions with immune modulating drugs also have
countervailing risks.
    These disorders also take an emotional and mental toll on the
person as well as on their families. Their quality of life may be
impacted because they no longer have the ability to do certain
activities that may affect or

highlight their skin disorder, such as swimming. Concerns over doctor
and hospital bills, particularly if a person's ability to work is
impacted, may further contribute to a person's emotional and mental
stress. While neither the precise reduction in individual risk of
developing this disorder from TCE exposure or the total number of cases
avoided can be estimated, this should be considered.
    b. Cancer effects: Non-Hodgkin's Lymphoma. EPA's 2011 IRIS
assessment for TCE found that TCE is carcinogenic. Chronic exposure to
TCE, by all routes of exposure, can result in non[hyphen]Hodgkin's
lymphoma (NHL), one of the three cancers for which the EPA IRIS TCE
assessment based its cancer findings. There are increased health risks
for NHL for the approximately 2,670 to 6,270 workers and 42,720 to
100,320 occupational bystanders exposed to TCE as a result of vapor
degreasing operations (Ref. 3).
    NHL is a form of cancer that originates in a person's lymphatic
system. For NHL, there are approximately 19.7 new cases per 100,000 men
and women per year with 6.2 deaths per 100,000 men and women per year.
NHL is the seventh most common form of cancer (Ref. 47). Some studies
suggest that exposure to chemicals may be linked to an increased risk
of NHL. Other factors that may increase the risk of NHL are medications
that suppress a person's immune system, infection with certain viruses
and bacteria, or older age (Ref. 48).
    Symptoms are painless, swollen lymph nodes in the neck, armpits or
groin, abdominal pain or swelling, chest pain, coughing or trouble
breathing, fatigue, fever, night sweats, and weight loss. Depending on
the rate at which the NHL is advancing, the approach may be to monitor
the condition, while more aggressive NHL could require chemotherapy,
radiation, stem cell transplant, medications that enhance a person's
immune system's ability to fight cancer, or medications that deliver
radiation directly to cancer cells.
    Treatment for NHL will result in substantial costs for hospital and
doctors' visits in order to treat the cancer. The treatments for NHL
can also have countervailing risks and can lead to higher
susceptibility of patients to secondary malignancies (Ref. 49). The
emotional and mental toll from wondering whether a treatment will be
successful, going through the actual treatment, and inability to do
normal activities or work will most likely be high. This emotional and
mental toll will extend to the person's family and friends as they
struggle with the diagnosis and success and failure of a treatment
regime. If a person has children, this could affect their mental and
emotional well-being and may impact their success in school. The
estimated value of the monetized benefit is $32 million to $201 million
at 3% and $15 million to $98 million at 7% annualized over 20 years.
    4. Reproductive and endocrine effects. The TCE risk assessment
identified risks of chronic non-cancer reproductive effects for workers
and bystanders exposed to TCE. There are increased health risks for
reproductive effects for the approximately 2,670 to 6,270 workers and
42,720 to 100,320 occupational bystanders exposed to TCE as a result of
vapor degreasing operations (Ref. 3).
    The reproductive effect for both females and males can be altered
libido. The prevalence of infertility is estimated at about 10-15% of
couples with a decreased libido among the factors of infertility (Ref.
50). For females, there can be reduced incidence of fecundability (6.7
million women ages 15 to 44 or 10.9% affected) (Ref. 51), increase in
abnormal menstrual cycles, and amenorrhea (the absence of
menstruation). Reproductive effects on males can be decreased potency,
gynaecomastia, impotence, and decreased testosterone levels, or low T
levels. Approximately 2.4 million men age 40 to 49 have low T levels,
with a new diagnosis of about 481,000 androgen deficiency cases a year.
Other estimates propose a hypogonadism prevalence of about 13 million
American men (Ref. 52). Low T levels are associated with aging; an
estimated 39% of men 45 or older have hypogonadism, resulting in low T
levels (Ref. 53). Hormone therapy and endocrine monitoring may be
required in the most severe cases.
    The monetary costs of these potential reproductive effects involve
doctor's visits in order to try to determine a diagnosis. In some
instances, a person or couple may need to visit a fertility doctor.
    The impact of a reduced sex drive can take an emotional and mental
toll on single people as well as couples. For people trying to get
pregnant, decreased fertility can add stress to a relationship as the
cause is determined and avenues explored to try to resolve the
difficulties in conceiving. A person or couples' quality of life can
also be affected as they struggle with a reduced sex drive. Similar to
other non-cancer effects discussed previously, while neither the
precise reduction in individual risk of developing this disorder from
reducing TCE exposure or the total number of cases avoided can be
estimated, the Agency still must consider their impact.
    5. Neurotoxicity. The TCE risk assessment identified neurotoxicity
risks for workers and bystanders from chronic TCE exposures. There are
increased health risks of neurotoxicity for the approximately 2,670 to
6,270 workers and 42,720 to 100,320 occupational bystanders exposed to
TCE as a result of vapor degreasing operations (Ref. 3).
    Studies have also demonstrated neurotoxicity from acute exposures.
Neurotoxic effects observed include alterations in trigeminal nerve and
vestibular function, auditory effects, changes in vision, alterations
in cognitive function, changes in psychomotor effects, and
neurodevelopmental outcomes. Developmental neurotoxicity effects
include delayed newborn reflexes, impaired learning or memory,
aggressive behavior, hearing impairment, speech impairment,
encephalopathy, impaired executive and motor function and attention
deficit (Ref. 4).
    The impacts of neurotoxic effects due to TCE exposure can last a
person's entire lifetime. Changes in vision may impact a person's
ability to drive, which can create difficulties for daily life.
Impaired learning or memory, aggressive behavior, hearing impairment,
speech impairment, encephalopathy, impaired executive and motor
function and attention deficit can impact a child's educational
progression and an adolescent's schooling and ability to make friends,
which in turn can impact the type of work or ability to get work later
in life.
    Neurotoxicity in adults can affect the trigeminal nerve, the
largest and most complex of the 12 cranial nerves, which supplies
sensations to the face, mucous membranes, and other structures of the
head. Onset of trigeminal neuralgia generally occurs in mid-life and
known causes include multiple sclerosis, sarcoidosis and Lyme disease.
There is also a co-morbidity with scleroderma and systemic lupus. Some
data show that the prevalence of trigeminal neuralgia could be between
0.01% and 0.3% (Ref. 54). Alterations to this nerve function might
cause sporadic and sudden burning or shock-like facial pain to a
person. One way to relieve the burning or shock-like facial pain is to
undergo a procedure where the nerve fibers are damaged in order to
block the pain. This treatment can have lasting impact on sensation
which may also be deleterious for normal pain sensation. The potential
side effects of this

procedure includes facial numbness and some sensory loss.
    The monetary health costs can range from doctor's visits and
medication to surgeries and hospital stays. Depending upon when the
neurotoxic effect occurred, the monetary costs may encompass a person's
entire lifetime or just a portion.
    The personal costs (emotional, mental, and impacts to a person's
quality of life) cannot be discounted. Parents of a child with impaired
learning, memory, or some other developmental neurotoxic effect may
suffer emotional and mental stress related to worries about the child's