# Trichloroethylene (TCE); Regulation of Use in Vapor Degreasing Under TSCA Section 6(a) > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2017-01229 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** January 19, 2017 - **Citation:** 82 FR 7432 ## Text 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. 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 Once submitted, comments cannot be edited or withdrawn.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: wheeler.cindy@epa.gov . For general information contact: The TSCA-Hotline, ABVI-Goodwill, 422 South Clinton Ave., Rochester, NY 14620; telephone number: (202) 554-1404; email address: TSCA-Hotline@epa.gov . 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‐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‐ and/or post-natal TCE exposures and potential adverse developmental outcomes. TCE‐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‐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‐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‐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‐dichlorovinyl‐L‐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‐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‐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‐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‐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‐related generalized skin diseases, jaundice, hepatomegaly, hepatosplenomegaly, and liver failure in TCE‐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‐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‐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‐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‐line. Batch cleaning machines are the most common type, while in‐line cleaners are typically used in large‐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‐cancer risks for workers who conduct TCE‐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)‐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‐fold ( i.e., 2‐fold for HEC50/HEC95 ratios; 3‐fold for HEC50/HEC99 ratios; 1.4‐fold for HEC95/HEC99 ratios). The IRIS TCE assessment used the HEC99 for the non‐cancer dose‐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 × 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 (§ 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 (§ 6(a)(2)). • Require minimum warning labels and instructions (§ 6(a)(3)). • Require record keeping or testing (§ 6(a)(4)). • Prohibit or regulate any manner or method of commercial use (§ 6(a)(5)). • Prohibit or otherwise regulate any manner or method of disposal (§ 6(a)(6)). • Direct manufacturers and processors to give notice of the determination to distributors and the public and replace or repurchase substances (§ 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‐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‐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 × 10 −1 for open top vapor degreasing systems to 1 × 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‐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 [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2017-01229. Public record. Not legal advice.