The document outlines the statutory requirements for the U.S. Environmental Protection Agency's risk-based screening process under the Toxic Substances Control Act, emphasizing the criteria for designating chemicals as high-priority or low-priority substances. By December 2019, the EPA aims to designate 20 high-priority chemicals for risk evaluations and 20 low-priority chemicals, focusing on factors like hazard, exposure, persistence, and potential risks to susceptible populations. Additionally, the prioritization process will prioritize chemicals from the 2014 TSCA work plan that have high toxicity and bioaccumulation scores.

1. PRIORITIZATION UNDER THE TOXIC
SUBSTANCES CONTROL ACT
Tala Henry
Office of Pollution Prevention and Toxics
U.S. Environmental Protection Agency
June 2018
henry.tala@ epa.gov

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Prioritization
Statutory Requirements
• EPA must establish a risk-based screening process, including criteria, for
designating a chemical substance as either:
– High-priority substance for risk evaluations
• may present an unreasonable risk of injury to health or the environment
because of a potential hazard and a potential route of exposure under the
conditions of use, including an unreasonable risk to a “potentially exposed or
susceptible subpopulation”, without consideration of costs or other non-risk
factors
– Low-priority substance for which risk evaluations are not warranted at the time
• based on information sufficient to establish that the chemical does not meet
the standard for high-priority
• By December 2019: 20 high-priority under evaluation + 20 low-priority designations

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• The process to designate the priority must include consideration of:
– hazard and exposure potential
– persistence and bioaccumulation
– potentially exposed or susceptible subpopulations
– storage near significant sources of drinking water
– the conditions of use or significant changes in the conditions of use
– the volume or significant changes in the volume
• Preference in designating priority substances:
– 2014 TSCA Work Plan chemicals (50% until complete) with persistence and
bioaccumulation scores of 3 (high) and that are know human carcinogens and
have high acute and chronic toxicity.
Prioritization
Statutory Requirements

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Prioritization Process and Timeline

5. Evaluating Risks of Existing Chemicals
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