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[Editor’s Note: This section is revised effective July, 2, 2024][New Text]
(a) Considerations. (1) Each risk evaluation will include all of the following components:
(i) A Scope, including a Conceptual Model and an Analysis Plan;
(ii) A Hazard Assessment;
(iii) An Exposure Assessment;
(iv) A Risk Characterization; and
(v) A Risk Determination.
(2) EPA guidance will be used, as applicable where it represents the best available science appropriate for the particular risk evaluation.
(3) Where appropriate, a risk evaluation will be conducted on a category of chemical substances. EPA will determine whether to conduct an evaluation on a category of chemical substances, and the composition of the category based on the considerations listed in 15 U.S.C. 2625(c).
(4) EPA will document that it has used the best available science and weight of scientific evidence approaches in the risk evaluation process.
(5) EPA will ensure that all supporting analyses and components of the risk evaluation are suitable for their intended purpose, and well-tailored to the problems and decision at hand, in order to inform the development of a technically sound determination as to whether a chemical substance presents an unreasonable risk of injury to health or the environment under the conditions of use within the scope of the risk evaluation, based on the weight of the scientific evidence.
(6) The extent to which EPA will refine its evaluations for one or more condition of use in any risk evaluation will vary as necessary to determine whether a chemical substance presents an unreasonable risk of injury to health or the environment.
(7) To the extent a determination as to the level of risk presented by a condition of use can be made, for example, using assumptions, uncertainty factors, and models or screening methodologies, EPA may determine that no further information or analysis is needed to complete its risk evaluation of the condition(s) of use.
(8) In general, EPA intends to determine whether a chemical substance does or does not present an unreasonable risk under all of the conditions of use within the scope of the risk evaluations, and intends to identify the individual conditions of use or categories of conditions of use that are responsible for such determinations.
(9) Within the time frame in §702.43(d), EPA will complete the risk evaluation of the chemical substance addressing all of the conditions of use within the scope of the evaluation. However, EPA may complete its evaluation of the chemical substance under specific conditions of use or categories of conditions of use at any point following the issuance of the final scope document, and issue its determination as to whether the chemical substance under those conditions of use does or does not present an unreasonable risk to health or the environment under those conditions of use. EPA will follow all of the requirements and procedures in this Subpart when it conducts its evaluation of the chemical substance under any individual or specific conditions of use.
(10) EPA will evaluate chemical substances that are metals or metal compounds in accordance with 15 U.S.C. 2605(b)(2)(E).
(b) Information and information sources. (1) EPA will base each risk evaluation on reasonably available information.
(2) EPA generally expects to initiate a risk evaluation for a chemical substance when EPA believes that all or most of the information necessary to perform the risk evaluation is reasonably available. EPA expects to use its authorities under the Act, and other information gathering authorities, when necessary to obtain the information needed to perform a risk evaluation for a chemical substance before initiating the risk evaluation for such substance. EPA will use such authorities on a case-by-case basis during the performance of a risk evaluation to obtain information as needed to ensure that EPA has adequate, reasonably available information to perform the evaluation.
(3) Among other sources of information, the Agency will consider information and advice provided by the Science Advisory Committee on Chemicals established pursuant to 15 U.S.C. 2625.
(4) In conducting risk evaluations, EPA will utilize reasonably available information including information, models, and screening methodologies, as appropriate. The approaches used will be determined by the quality of the information, the deadlines specified in TSCA section 6(b)(4)(G) for completing the risk evaluation, and the extent to which the information reduces uncertainty.
(5) Where appropriate, to the extent practicable, and scientifically justified, EPA will require the development of information generated without the use of new testing on vertebrates in performing risk evaluation.
(c) Scope of the risk evaluation. The scope of the risk evaluation will include all the following:
(1) The condition(s) of use, as determined by the Administrator, that the EPA plans to consider in the risk evaluation.
(2) The potentially exposed populations, including any potentially exposed or susceptible subpopulations as identified as relevant to the risk evaluation by the Agency under the conditions of use, 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.
(3) A description of the reasonably available information and science approaches EPA plans to use in the risk evaluation.
(4) A conceptual model:
(i) The scope documents will include a Conceptual Model that describes actual or predicted relationships between the chemical substance, the conditions of use within the scope of the evaluation and human and environmental receptors.
(ii) The conceptual model will identify human and ecological health hazards the EPA plans to evaluate for the exposure scenarios EPA plans to evaluate.
(iii) Conceptual model development will consider the life cycle of the chemical substance, including manufacture, processing, distribution in commerce, storage, use, and disposal, relevant to the conditions of use within the scope of the evaluation
(5) An analysis plan:
(i) The scope documents will include an analysis plan that identifies the approaches, methods, and/or metrics that EPA plans to use to assess exposures, effects, and risk, including associated uncertainty and variability for each risk evaluation. The analysis plan will also identify the strategy for using information, accepted science policies, models, and screening methodologies.
(ii) Hypotheses about the relationships identified in the conceptual model will be described. The relative strengths of alternative hypotheses if any will be evaluated to determine the appropriate risk assessment approaches.
(6) The Agency's plan for peer review.
(7) Developing the scope.
(i) Draft scope. For each risk evaluation to be conducted EPA will publish a document in the Federal Register that specifies the draft scope of the risk evaluation the Agency plans to conduct. The document will address the elements in paragraphs (c)(1) through (6) of this section.
(ii) Timeframes. EPA generally expects to publish the draft scope no later than 3 months from the initiation of the risk evaluation process for the chemical substance.
(iii) Public comments. EPA will allow a public comment period of no less than 45 calendar days during which interested persons may submit comment on EPA's draft risk evaluation scope. EPA will open a docket to facilitate receipt of public comments.
(8) Final scope:
(i) The Agency will, no later than 6 months after the initiation of a risk evaluation, publish a document in the Federal Register that specifies the final scope of the risk evaluation the Agency plans to conduct. The document shall address the elements in paragraphs (c)(1) through (6) of this section.
(ii) For a chemical substance designated as a High-Priority Substance under subpart A of this part, EPA will not publish the final scope of the risk evaluation until at least 12 months have elapsed from the initiation of the prioritization process for the chemical substance.
(d) Hazard assessment. (1) The hazard information relevant to the chemical substance will be evaluated using hazards identified in the final scope document published pursuant to paragraph (c)(8) of this section, for the identified exposure scenarios, including any identified potentially exposed or susceptible subpopulation(s).
(2) The hazard assessment process will identify the types of hazards to health or the environment posed by the chemical substance under the condition(s) of use within the scope of the risk evaluation. Hazard information related to potential health and environmental hazards of the chemical substance will be reviewed in a manner consistent with best available science and weight of scientific evidence as defined in §702.33 and all assessment methods will be documented. This process includes the identification, evaluation, and synthesis of information to describe the potential health and environmental hazards of the chemical substance.
(3) Relevant potential human and environmental hazards will be evaluated.
(4) The relationship between the dose of the chemical substance and the occurrence of health and environmental effects or outcomes will be evaluated.
(5) Studies evaluated may include, but would not be limited to: Human epidemiological studies, in vivo and/or in vitro laboratory studies, biomonitoring studies, mechanistic and/or kinetic studies in a variety of test systems, including but not limited to toxicokinetics and toxicodynamics, computational toxicology such as high-throughput assays, genomic response assays, data from structure-activity relationships, and ecological field data.
(6) Hazard identification will include an evaluation of the strengths, limitations, and uncertainties associated with the reasonably available information.
(7) The human health hazard assessment will consider all potentially exposed and susceptible subpopulation(s) determined to be relevant, as identified in the final scope document published pursuant to paragraph (c)(8) of this section.
(8) The environmental health hazard assessment will consider the relationship between the chemical substance and the occurrence of an ecological hazard elicited.
(e) Exposure assessment. (1) Where relevant, the likely duration, intensity, frequency, and number of exposures under the conditions of use will be considered.
(2) Chemical-specific factors including, but not limited to: Physical- chemical properties and environmental fate and transport parameters will be examined.
(3) Exposure information related to potential human health or ecological hazards of the chemical substance will be reviewed in a manner consistent with the description of best available science and weight of scientific evidence in §702.33 and all methods will be documented.
(4) The human health exposure assessment will consider all potentially exposed and susceptible subpopulation(s) determined to be relevant, as identified in the final scope document published pursuant to paragraph (c)(8) of this section.
(5) Environmental health exposure assessment:
(i) The environmental health exposure assessment will characterize and evaluate the interaction of the chemical substance with the ecological receptors identified in the final scope document published pursuant to paragraph (c)(8) of this section.
(ii) Exposures considered will include populations and communities, depending on the chemical substance and the ecological characteristic involved.
[82 FR 33750, July 20, 2017; 89 FR 37052, May 3, 2024]