The U.S. Environmental Protection Agency (EPA) released the final risk evaluation for trichloroethylene (TCE) on November 23, 2020. 85 Fed. Reg. 75010 (Nov. 24, 2020). Of the 54 conditions of use that EPA reviewed, EPA found that 52 present an unreasonable risk to workers, occupational non-users (ONU), consumers, and bystanders. EPA determined that distribution in commerce and consumer use of TCE in pepper spray do not present an unreasonable risk. EPA also found no unreasonable risks to the environment.

EPA’s next step in the process required by the Toxic Substances Control Act (TSCA) is to develop a plan to reduce or eliminate the unreasonable risks found in the final risk evaluation. EPA states that it “is moving immediately to risk management for this chemical and will work to propose and finalize actions to protect workers, occupational non-users, consumers, and bystanders.” The potential actions that EPA could take to address these risks include regulating how TCE is used or limiting or prohibiting the manufacture, processing, distribution in the marketplace, use, or disposal of TCE, as applicable. As with any chemical product, EPA “strongly recommends that users of products containing TCE continue to carefully follow all instructions on the product’s label and safety data sheet.”

Background

TSCA Section 6, as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act (Lautenberg Act), requires EPA to conduct risk evaluations to “determine whether a chemical substance presents an unreasonable risk of injury to health or the environment, without consideration of costs or other nonrisk factors, including an unreasonable risk to a potentially exposed or susceptible subpopulation identified as relevant to the risk evaluation by the Administrator, under the conditions of use.” The statute identifies the minimum components EPA must include in all risk evaluations. For each risk evaluation, EPA must publish a document that outlines the scope of the risk evaluation to be conducted, which includes the hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations that EPA expects to consider. Each risk evaluation must also: (1) integrate and assess available information on hazards and exposure for the conditions of use of the chemical substance, including information on specific risks of injury to health or the environment and information on relevant potentially exposed or susceptible subpopulations; (2) describe whether aggregate or sentinel exposures were considered and the basis for that consideration; (3) take into account, where relevant, the likely duration, intensity, frequency, and number of exposures under the conditions of use; and (4) describe the weight of the scientific evidence for the identified hazards and exposure. The risk evaluation must not consider costs or other nonrisk factors. A detailed summary and analysis of the final risk evaluation rule is available in our June 26, 2017, memorandum, “EPA Issues Final TSCA Framework Rules.”

Risk Evaluation for TCE

According to the final risk evaluation, EPA evaluated TCE’s occupational conditions of use, including the following categories: manufacture; import; processing as a reactant/intermediate; incorporation into formulation; mixture or reaction product; incorporated into articles; repackaging; recycling; distribution; solvents for cleaning and degreasing; lubricants and greases; adhesives and sealants; functional fluids in a closed system; paints and coatings; cleaning and furniture care products; laundry and dishwashing products; arts, crafts, and hobby materials; corrosion inhibitors and anti-scaling agents; processing aids; ink, toner, and colorant products; automotive care products; apparel and footwear care products; other uses; and disposal. EPA evaluated the following categories of consumer conditions of use: solvents for cleaning and degreasing; lubricants and greases; adhesives and sealants; cleaning and furniture care products; arts, crafts, and hobby materials; apparel and footwear care products; and other consumer uses. According to the final risk evaluation, consistent with the decision at the problem formulation stage, EPA excluded consumer uses of paint and coatings from the scope of the evaluation.

EPA did not identify any “legacy uses” (i.e., circumstances associated with activities that do not reflect ongoing or prospective manufacturing, processing, or distribution) or “associated disposal” (i.e., future disposal from legacy uses) of TCE. Therefore, EPA did not add any such uses or disposals to the scope of the risk evaluation for TCE following the issuance of the opinion in Safer Chemicals, Healthy Families v. EPA. The final risk evaluation states that EPA did not evaluate “legacy disposal” (i.e., disposals that have already occurred) in the risk evaluation “because legacy disposal is not a ‘condition of use’ under Safer Chemicals.”

EPA made the following risk evaluation findings. EPA states that in making these unreasonable risk determinations, it considered the hazards and exposure, magnitude of risk, exposed population, severity of the hazard, uncertainties, and other factors.

• EPA found unreasonable risks to human health from 52 out of 54 conditions of use of TCE:
   
  • Consumers and Bystanders: EPA found unreasonable risks to consumers and bystanders from all but one consumer use of TCE. Consumer uses include cleaning and furniture care products, arts and crafts spray coatings, and automotive care products like brake cleaners. EPA states that risks to consumers can come from short-term inhalation and dermal exposure. EPA notes that it did not find consumer use of pepper spray to present an unreasonable risk; and
     
  • Workers and ONUs: EPA found unreasonable risks to workers from all occupational uses of TCE, except for distribution in commerce. Additionally, EPA found unreasonable risks from most commercial uses of TCE to ONUs. According to EPA, common commercial uses are as a solvent in industrial cleaning/degreasing, an ingredient in adhesive/sealant removers, in paints and coatings, and in automotive care products like brake cleaners. Risks to workers and ONUs can come from both short- and long-term inhalation and dermal exposure.
     
• EPA found no unreasonable risk to the environment for any conditions of use. EPA assessed the impact of TCE on aquatic and sediment-dwelling organisms through surface water and sediment exposures and to terrestrial organisms. After reviewing these data, EPA states that it found no unreasonable risks to the environment.
   

Commentary

The final TCE risk evaluation is remarkable because of the breadth of the conditions of use for which EPA identified unreasonable risk. EPA identified exceedances of risk thresholds by inhalation and dermal exposures at the high-end and central tendencies, both with and without protective equipment, and across health endpoints, including acute (developmental and immunosuppression), chronic, and cancer endpoints -- not just limited to the congenital heart effects that some have viewed as controversial. Risks were found across consumer, commercial, and industrial conditions of use for workers, ONUs, consumers, and bystanders.

It remains to be seen how EPA will proceed with risk management. It seems that all consumer uses of TCE, except perhaps for the pepper spray use, are likely to face a ban. Given the breadth of the risks identified by EPA for occupational conditions of use, release and exposure controls will have to be remarkably stringent to address the one-to-three orders of magnitude of exceedances for some of the conditions of use. In fact, TCE may be the first of the first ten risk evaluations in which EPA will consider seriously a broad ban for manufacturing, processing, and use. EPA will then have to evaluate whether technically feasible alternatives exist for TCE in each of its many uses.