Background on Risk Evaluation Under the Toxic Substances Control Act (TSCA): Perchloroethylene

INSIGHTi

Background on Risk Evaluation Under the

Toxic Substances Control Act (TSCA):

Perchloroethylene

September 12, 2022

In 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act (LCSA; P.L. 114-182)

amended Title I of the Toxic Substances Control Act (TSCA; 15 U.S.C. §2601 et seq.) to direct the U.S.

Environmental Protection Agency (EPA) to systematically prioritize chemicals for risk evaluation. (For

more information, see CRS Report R45149, Title I of the Toxic Substances Control Act (TSCA): A

Summary of the Statute.) The purpose of the risk evaluations is to determine whether particular chemicals

warrant regulation in terms of the risks associated with their manufacture, processing, distribution, use, or

disposal. If EPA identifies “unreasonable” risk to human health or the environment associated with one or

more of the elements of a chemical’s lifecycle, TSCA Section 6 directs EPA to promulgate a rule to

mitigate those risks. TSCA Section 9 limits EPA’s authority to regulate a chemical under TSCA if another

law may be used to regulate a chemical for the unreasonable risk identified by the agency.

As amended, TSCA Section 6 directed EPA to select 10 chemicals for risk evaluation from a list of 90

chemicals that the agency identified in 2014 as warranting risk assessment. EPA based this list on a

screening of 345 chemicals for potential hazard and exposure, and persistence and bioaccumulation

characteristics. With more than 86,000 chemicals on the TSCA Inventory, EPA’s screening approach was

intended to focus the agency’s resources and attention on a select group of chemicals for which sufficient

scientific and technical information is available to suggest greater concern to human health or the

environment. Pursuant to TSCA Section 6, EPA selected the initial 10 chemicals for risk evaluation,

including perchloroethylene (PCE), in 2016 (81 Federal Register 91927-91929, December 19, 2016).

Each chemical substance that EPA evaluates has unique properties, uses, and risks, which may warrant

different risk management approaches. The process of conducting risk evaluations and assessing risk

management options involves judgments about the reliability of available scientific and technical

information. Aspects of this process and what information EPA identifies as the basis for justifying certain

regulatory action can generate disagreement between the agency and stakeholders (e.g., industry,

environmental and public health organizations). As EPA continues to implement TSCA, the agency’s risk

evaluations and related actions are likely to receive scrutiny among stakeholders. Congress may consider

assessing EPA’s implementation of TSCA, as amended by the LCSA, and the resulting outcomes from the

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agency’s actions and decisions. The next section discusses EPA’s risk evaluation for PCE and potential

next steps toward addressing the unreasonable risks that the agency identified.

Perchloroethylene (PCE)

In 2016, EPA selected PCE (CAS Number 127-81-4) as one of the initial 10 chemicals for a risk

evaluation. According to EPA, over 300 million pounds of PCE are manufactured in, or imported to, the

United States annually. The predominant use of PCE is for the manufacture of industrial gases and

fluorinated chemicals. PCE is also used as a solvent for dry cleaning, vapor degreasing, and other

miscellaneous uses. The TSCA risk evaluation builds upon existing scientific understanding of the risks

associated with PCE to determine whether there may be unreasonable risks associated with current uses

of PCE that may warrant additional control.

In December 2020, EPA finalized its risk evaluation for PCE, identifying unreasonable risks to the health

of workers, occupational non-users, consumers, and bystanders from 59 of 61 conditions of use evaluated.

EPA did not identify unreasonable risks to the environment for the conditions of use evaluated by the

agency. EPA based its risk determinations on a comparison of various sources of scientific information.

EPA considered the predicted exposure to PCE from various exposure scenarios (e.g., workers involved in

handling the chemical with or without the use of a respirator), the estimated level of exposure expected

not to result in the development of adverse noncarcinogenic health effects while taking into account a

margin of exposure, and the estimated level of exposure expected not to increase the risk of developing

particular cancers above certain guideline ranges (i.e., 1-in-10,000 to 1-in-a-million above background

risk). EPA’s risk determinations regarding potential environmental effects are based the predicted

exposure to PCE for various species compared to the estimated level of exposure expected not to result in

the development of adverse effects in species at the population level.

In June 2021, EPA announced its intention to approach the TSCA unreasonable risk determinations by

making one determination for a chemical substance rather than multiple determinations for each condition

of use. In June 2022, EPA released a draft revised risk determination for PCE, which indicates that the

chemical presents unreasonable risks to human health. This revised risk determination would supersede

the December 2020 risk determinations in the risk evaluation.

Given that EPA identified unreasonable risks associated with PCE, the agency is developing a rule under

TSCA Section 6 to address such risks. Section 6(a) identifies seven risk management options that EPA

may use alone or in combination to address the risks of PCE, including prohibiting the manufacture of the

chemical and requiring manufacturers of the chemical to communicate the chemical’s risks to allow

downstream processors, users, and distributors the opportunity to take applicable protective measures. In

developing the rule, EPA is required pursuant to Section 6 to identify various risk management options

that would adequately address the identified unreasonable risk and determine the associated costs for each

proposed risk management option.

In its risk evaluation, EPA acknowledged multiple existing regulations that apply to PCE. These

regulations (e.g., occupational standards, stationary source air emissions standards, and drinking water

standards) were promulgated under various statutes that EPA and other agencies administer. A TSCA risk

management rule could supplement these existing regulations.

Since PCE is manufactured at relatively high volumes, those who manufacture and use PCE are likely to

scrutinize the forthcoming risk management rule and underlying risk evaluation. Congress may conduct

oversight or consider legislation with regard to EPA’s efforts to manage risks associated with PCE and

whether such efforts are aligned with the intent of the TSCA amendments.

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Author Information

Jerry H. Yen

Analyst in Environmental Policy

Disclaimer

This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff

to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of

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information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.

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