Section 702.39 - Components of risk evaluation(a)In general. Each risk evaluation will include all of the following components:(3) An Exposure Assessment;(4) A Risk Characterization; and(5) A Risk Determination.(b)Scope of the risk evaluation. The scope of the risk evaluation will include all the following:(1) The condition(s) of use the EPA expects 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 EPA under the conditions of use that EPA plans to evaluate.(3) The ecological receptors that EPA plans to evaluate.(4) The hazards to health and the environment that EPA plans to evaluate.(5) A description of the reasonably available information and scientific approaches EPA plans to use in the risk evaluation.(6) A conceptual model that describes the actual or predicted relationships between the chemical substance, its associated conditions of use through predicted exposure scenarios, and the identified human and environmental receptors and human and ecological health hazards.(7) An analysis plan that includes hypotheses and descriptions about the relationships identified in the conceptual model and the approaches and strategies EPA intends to use to assess exposure and hazard effects, and to characterize risk; and a description, including quality, of the data, information, methods, and models, that EPA intends to use in the analysis and how uncertainty and variability will be characterized.(8) EPA's plan for peer review consistent with § 702.41 .(c)Hazard assessment.(1) The hazard assessment process includes the identification, evaluation, and synthesis of information to describe the potential health and environmental hazards of the chemical substance under the conditions of use.(2) Hazard information related to potential health and environmental hazards of the chemical substance will be reviewed in a manner consistent with best available science based on the weight of scientific evidence and all assessment methods will be documented.(3) Consistent with § 702.37(b) , information evaluated may include, but would not be limited to: Human epidemiological studies, in vivo and/or in vitro laboratory studies, biomonitoring and/or human clinical studies, ecological field data, read across, mechanistic and/or kinetic studies in a variety of test systems. These may include but are not limited to: toxicokinetics and toxicodynamics (e.g., physiological-based pharmacokinetic modeling), and computational toxicology (e.g., high-throughput assays, genomic response assays, data from structure-activity relationships, in silico approaches, and other health effects modeling).(4) The hazard information relevant to the chemical substance will be evaluated for identified human and environmental receptors, including all identified potentially exposed or susceptible subpopulation(s) determined to be relevant, for the exposure scenarios relating to the conditions of use.(5) The relationship between the dose of the chemical substance and the occurrence of health and environmental effects or outcomes will be evaluated.(6) Hazard identification will include an evaluation of the strengths, limitations, and uncertainties associated with the reasonably available information.(d)Exposure assessment.(1) Where relevant, the likely duration, intensity, frequency, and number of exposures under the conditions of use will be considered.(2) Exposure information related to potential human health or ecological hazards of the chemical substance will be reviewed in a manner consistent with best available science based on the weight of scientific evidence and all assessment methods will be documented.(3) Consistent with § 702.37(b) , information evaluated may include, but would not be limited to: chemical release reports, release or emission scenarios, data and information collected from monitoring or reporting, release estimation approaches and assumptions, biological monitoring data, workplace monitoring data, chemical exposure health data, industry practices with respect to occupational exposure control measures, and exposure modeling.(4) Chemical-specific factors, including, but not limited to physical-chemical properties and environmental fate and transport parameters, will be examined.(5) The human health exposure assessment will consider all potentially exposed or susceptible subpopulation(s) determined to be relevant.(6) Environmental health exposure assessment will characterize and evaluate the interaction of the chemical substance with the ecological receptors and the exposures considered, including populations and communities, depending on the chemical substance and the ecological characteristic involved.(7) EPA will describe whether sentinel exposures under the conditions of use were considered and the basis for their consideration.(8) EPA will consider aggregate exposures to the chemical substance, and, when supported by reasonably available information, consistent with the best available science and based on the weight of scientific evidence, include an aggregate exposure assessment in the risk evaluation, or will otherwise explain in the risk evaluation the basis for not including such an assessment.(9) EPA will assess all exposure routes and pathways relevant to the chemical substance under the conditions of use, including those that are regulated under other federal statutes.(e)Risk characterization.(1)Requirements. To characterize the risks from the chemical substance, EPA will:(i) Integrate the hazard and exposure assessments into quantitative and/or qualitative estimates relevant to specific risks of injury to health or the environment, including any potentially exposed or susceptible subpopulations identified, under the conditions of use;(ii) Not consider costs or other non-risk factors; and(iii) Describe the weight of the scientific evidence for the identified hazards and exposures.(2)Summary of considerations. EPA will summarize, as applicable, the considerations addressed throughout the evaluation components, in carrying out the obligations under 15 U.S.C. 2625(h) . This summary will include, as appropriate, a discussion of:(i)Considerations regarding uncertainty and variability. Information about uncertainty and variability in each step of the risk evaluation (e.g., use of default assumptions, scenarios, choice of models, and information used for quantitative analysis) will be integrated into an overall characterization and/or analysis of the impact of the uncertainty and variability on estimated risks. EPA may describe the uncertainty using a qualitative assessment of the overall strength and limitations of the data and approaches used in the assessment.(ii)Considerations of data quality. A discussion of data quality (e.g., reliability, relevance, and whether methods employed to generate the information are reasonable for and consistent with the intended use of the information), as well as assumptions used, will be included to the extent necessary. EPA also expects to include a discussion of the extent of independent verification or peer review of the information or of the procedures, measures, methods, protocols, methodologies, or models used in the risk evaluation.(iii)Considerations of alternative interpretations. If appropriate and relevant, where alternative interpretations are plausible, a discussion of alternative interpretations of the data and analyses will be included.(iv)Additional considerations for environmental risk. For evaluation of environmental risk, it may be necessary to discuss the nature and magnitude of the effects, the spatial and temporal patterns of the effects, implications at the individual, species, population, and community level, and the likelihood of recovery subsequent to exposure to the chemical substance.(f)Risk determination.(1) As part of the risk evaluation, EPA will make a single determination as to whether the chemical substance presents an unreasonable risk of injury to health or the environment, without consideration of costs or other non-risk factors, including an unreasonable risk to a potentially exposed or susceptible subpopulation, under the conditions of use.(2) In determining whether unreasonable risk is presented, EPA's consideration of occupational exposure scenarios will take into account reasonably available information, including known and reasonably foreseen circumstances where subpopulations of workers are exposed due to the absence or ineffective use of personal protective equipment. EPA will not consider exposure reduction based on assumed use of personal protective equipment as part of the risk determination.(3) EPA will determine whether a chemical substance does or does not present an unreasonable risk after considering the risks posed under the conditions of use and, where EPA makes a determination of unreasonable risk, EPA will identify the conditions of use that significantly contribute to such determination.82 FR 33747, 9/18/2017; 89 FR 37052, 7/2/2024