In accordance with implementing regulations for the Toxic Substances Control Act (TSCA), the Environmental Protection Agency (EPA) is requesting public comment on the draft scope document of the risk evaluation to be conducted for octamethylcyclotetra-siloxane (D4).

 The solicitation of comment comes following a manufacturer request for the risk evaluation under 40 CFR 702.37. The D4 chemical is used to make other silicone chemicals and as an ingredient in some personal care products. Through the risk evaluation process, EPA determines whether a chemical substance presents an unreasonable risk of injury to health or the environment under the conditions of use, as determined by the Administrator, in accordance with TSCA section 6(b)(4).

The draft scope includes the conditions of use, hazards, exposures, and the potentially exposed or susceptible subpopulations that EPA plans to consider in conducting the risk evaluation (15 U.S.C. 2605(b)(4)(D)) of this chemical substance. The 45-calendar day comment period on the draft scope allows the public to provide additional data or information that could be useful to the Agency in finalizing the scope of the risk evaluation. Comments can be submitted, identified by docket identification number EPA-HQ-OPPT-2018-0443, online using the Federal eRulemaking Portal (comments must be received on or before October 25, 2021).

This action is directed to the public in general and may be of interest to entities that manufacture (including import) a chemical substance regulated under TSCA, 15 U.S.C. 2601 et seq., (e.g., entities identified under North American Industrial Classification System (NAICS) codes 325 and 324110.) The action may also be of interest to chemical processors, distributors in commerce, and users; non-governmental organizations in the environmental and public health sectors; state and local government agencies; and members of the public. Since other entities and corresponding NAICS codes for entities that may be interested in or affected by this action.

As part of the risk evaluation process, EPA must evaluate both hazards and exposures for the conditions of use; describe whether aggregate or sentinel exposures were considered and the basis for consideration; not consider costs or other non-risk factors; take into account where relevant, likely duration, intensity, frequency, and number of exposures; and describe the weight-of-scientific-evidence for hazards and exposures (15 U.S.C. 2605(b)(4)(F)). This process will culminate in a determination of whether or not the chemical substance presents an unreasonable risk of injury to health or the environment under the conditions of use (15 U.S.C. 2605(b)(4)(A); 40 CFR 702.47).

The draft scope of the risk evaluation includes the following components (40 CFR 702.41(c)):

• The potentially exposed populations that EPA plans to evaluate; the ecological receptors that EPA plans to evaluate; and the hazards to health and the environment that EPA plans to evaluate.
• A description of the reasonably available information and the science approaches that the Agency plans to use.
• A conceptual model that will describe the actual or predicted relationships between the chemical substance, the conditions of use within the scope of the evaluation and the receptors, either human or environmental, with consideration of the life cycle of the chemical substance – from manufacturing, processing, distribution in commerce, storage, use, to release or disposal – and identification of human and ecological health hazards EPA plans to evaluate for the exposure scenarios EPA plans to evaluate.
• An analysis plan, which will identify the approaches and methods EPA plans to use to assess exposure, hazards, and risk, including associated uncertainty and variability, as well as a strategy for using reasonably available information and science approaches.
• A plan for peer review.

EPA encourages commenters to provide information they believe might be missing or may further inform the risk evaluation. EPA will publish a notice in the Federal Register announcing the availability of the final scope of the risk evaluation within three months of publishing the draft scope.

At RHP Risk Management, we help our clients navigate the uncertainties associated with environmental and occupational hazards and risks and can assist with updating an employer’s hazard communication program, chemical inventory document management, and hazard communication training to ensure regulatory compliance. Our staff of public health professionals are experienced and trained in recognizing, anticipating and controlling hazards. For more information on RHP’s services and contact information, please contact Jacob Persky, MPH, CIH at jpersky@rhprisk.com, (773) 867-6001 or Ben Heckman, MPH, CIH at bheckman@rhprisk.com, (717) 706-3847 and visit rhprisk.com.