On January 19, 2017, the U.S. Environmental Protection Agency (EPA) published a proposal for procedures to conduct chemical risk evaluations under TSCA. 82 Fed Reg. 7,562. Chemical risk evaluations follow “Prioritization” in a new process for reviewing chemical substances under amended TSCA. The Agency must conduct scheduled evaluations to determine whether high priority chemicals present an unreasonable risk of injury to health or the environment under the conditions of use (including “reasonably foreseen” uses). No consideration can be given to cost or other non-risk factors, while special consideration must be given to potentially exposed and susceptible subpopulations, including infants, children, pregnant women, workers, and the elderly. Under this proposed rule, the phases of a chemical risk evaluation would include scope, hazard assessment, exposure assessment, risk characterization, and a final determination. Comments on the proposal must be received by March 20, 2017.


On June 22, 2016, TSCA was amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act (LCSA). Under the original TSCA, EPA administered health and safety reviews for new chemical substances before they entered the marketplace, while chemical substances in existence at the time the TSCA Chemical Substance Inventory (Inventory) was first published in 1979 were “grandfathered in” without EPA review. The LCSA includes a requirement for EPA to assess the health and environmental risks of existing chemicals and manage identified risks.


The chemical substances subject to risk evaluation are the first ten chemicals named in EPA’s November 29, 2016 announcement, chemical substances with a “high-priority” designation under the prioritization process, and chemical substances for which manufacturers request risk evaluations. EPA is proposing two specific requirements for manufacturers to include in submitted requests: (1) a showing that there is sufficient, reasonably available information for EPA to conduct a risk evaluation under the conditions of use; and (2) a complete and accurate list of reasonably available information on hazards and exposure of the chemical for all conditions of use, including copies of publicly unavailable cited information.

Procedures and Timing

EPA proposes to conduct the risk evaluation in four steps followed by an opportunity for peer review. In the first “scoping” phase, EPA will identify conditions of use, hazards, exposures, and any potentially exposed or susceptible subpopulations expected to be considered in its evaluation. EPA is also proposing to include in this phase the models, screening methods, and accepted science policies it anticipates using in its evaluation; the potential hazards throughout the life cycle of the chemical substance; and an analysis plan that details the results of the assessment including the effects and risks of exposure. A draft scoping document will be available for public comment for 45 days before the final scope is published. EPA has taken the position that any issue related to the scope not raised during the comment period cannot be raised later as an objection or challenge in future administrative or judicial proceedings. Industry must, therefore, be prepared to identify known, intended or reasonably foreseen uses early on in the process.

Given time constraints in the statutory schedule, EPA is not issuing a draft scope for the initial 10 chemical risk evaluations. However, the Agency held a public meeting on February 14, 2017 to receive information related to the conditions of use for the first ten chemicals scheduled for risk evaluation, and comments can be submitted to the public docket as we discuss here[AMT1] .

In the second, hazard assessment phase, EPA proposes to identify the chemical’s health and environmental effects and characterize the “quality” and “weight of evidence” of the supporting data, although EPA has declined to define these terms. The Agency plans to rely on “dose-response” assessments among other relevant scientific methodologies.

The third phase requires an exposure assessment in which “reasonably available” information will be used to estimate likely duration, intensity, frequency, and consistency of exposure under the conditions of use, as well as the size, nature, and types of individuals or populations at risk for exposure. EPA proposes to define “reasonably available” as information that already exists and that is already in its possession or can be reasonably obtained.

In the next phase, a draft risk evaluation will be open for public comment for at least 30 days. Then, EPA will publish a fully integrated risk characterization, which will include an analysis from each previous phase, assumptions and uncertainties, and a judgment as to the presence or absence of risks. In a meeting with industry, EPA stated that it would make a final risk determination on every single use considered in the scoping document. Risk evaluations will be subject to independent peer review from experts who did not contribute to the process, in accordance with the EPA Peer Review Handbook.

With regard to manufacturer requests, EPA is proposing to verify the validity of a request, to announce a request within 30 days of receipt, and to allow another 30 days for public comments. Within 9 months, EPA will further review the request, all information and commentary submitted, and either request additional information or begin the risk evaluation process. Failure to submit any additional information requested will result in a “High-Priority” designation for that particular substance under the prioritization process.

Opportunity to Comment

The proposed rule is open for comment until March 20, 2017. Potential issues to consider for comments include the lack of:

(1) criteria for risk evaluation;

(2) definitions for data quality and weight of evidence review;

(3) a definitive standard for “unreasonable risk”; and/or

(4) criteria for identifying potentially exposed or susceptible subpopulations beyond infants, children, pregnant women, workers, and the elderly.

Please contact us immediately if you are interested in submitting comments.