EPA Publishes Proposed TSCA Prioritization Rule

JANUARY 26, 2017

EPA has published its proposed rule on its internal, risk-based procedures for the prioritization of existing chemicals for risk evaluation under TSCA as either “High-Priority Substances” for risk evaluation, or “Low-Priority Substances” for which risk evaluations are not warranted at the time. Prioritization is the initial step in the new process of existing chemical substance review and risk management activity established by last year’s TSCA amendments.

The revised TSCA requires that the prioritization process for a single chemical last no less than nine months, but no more than 12 months. The Agency used the methodology from its TSCA Work Plan to inform the development of this proposed rule.

“High-Priority Substance” means a chemical substance, without consideration of costs or other non-risk factors, 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 potentially exposed or susceptible subpopulations identified as relevant by EPA. “Low-Priority Substance” means a chemical substance that does not meet the standard for a High-Priority Substance. ?

EPA is proposing four steps for prioritization: pre-prioritization, initiation, proposed designation and final designation:

      (1) During the pre-prioritization stage, EPA will screen chemicals against criteria contained within the revised law (e.g., persistence and bioaccumulation, potentially exposed subpopulations, storage near significant sources of drinking water, conditions of use, and production volume). The Agency notes that it would like to have an initial concept of certain key chemical characteristics before the initiation phase, which starts the statutory-deadline “clock.”

      (2) During the initiation phase, EPA will identify a chemical substance in the Federal Register and allow for a 90-day comment period for industry and the public to submit information to inform the Agency’s proposed designation of a substance as either high or low priority.

      (3) Once all relevant information and data are submitted, EPA will make a preliminary determination that a chemical is high or low priority and will publish that proposed designation in the Federal Register and allow for a second 90-day comment period, along with the information, data, and analyses used to reach the proposed designation.

  (4) Once comments are reviewed, EPA will make its final substance designation. High-priority chemicals will then be subject to risk evaluations while EPA will not take further action on a low-priority substance. EPA notes that its proposed default rule will be to high priority in circumstances where insufficient data are available to make an alternative determination.

It is important to note that final designation of a chemical substance as a High-Priority Substance requires EPA then to conduct a risk evaluation for that chemical substance. Stated differently, a High-Priority Substance designation does not mean that the chemical substance presents a risk to human health or the environment; rather, it means that EPA intends to consider the chemical substance for further risk review and evaluation.

In addition to requesting comment on its overall proposed prioritization process, EPA also requests input in its proposed rule as to whether explicit definitions are appropriate for key terms such as “best available science,” “weight of the evidence,” “sufficiency of the information,” “unreasonable risk,” and “reasonable available information” The Agency asserts that explicitly defining those terms is unnecessary from its vantage point, but wants further input.

ILMA will submit comments before the March 20, 2017 deadline.