EPA Considers First 10 Chemicals for Risk Evaluation under Amended TSCA
August 29, 2017 •
The U.S. Environmental Protection Agency (EPA) is considering the first 10 chemicals undergoing risk evaluation under the amended Toxic Substances Control Act (TSCA). The agency will be accepting comments on the chemical/clusters through Sept. 19. ACA is seeking input from its members on comments. Based on comment, EPA will refine scoping documents published earlier this summer to publish draft problem formulations as the next step in risk evaluation. Upon publication, EPA intends to accept public comment on problem formulations, prior to proceeding to risk evaluation. EPA is offering this interim step for the first 10 risk evaluations since there was insufficient time for comment on scoping documents during the last public comment period.
EPA’s scoping documents will shape evaluations of the first 10 chemicals for initial risk evaluation: asbestos; pigment violet 29; 1,4-dioxane; cyclic aliphatic bromides cluster; carbon tetrachloride; 1-bromopropane; methylene chloride; n-methylpyrrolidone; trichloroethylene; and tetrachloroethylene.
The Frank R. Lautenberg Chemical Safety for the 21st Century Act, signed into law on June 22, 2016, mandates the agency to restrict chemicals already in commerce that pose unreasonable risks to public health and the environment.
The following addresses some EPA considerations for the first risk evaluations as described in initial scoping documents, including what the agency deems associated hazards for chemicals.
First 10 Chemicals for Risk Evaluation
In the risk evaluation for NMP, EPA expects to consider the following potentially exposed groups of human receptors: workers, occupational non-users, consumers, and bystanders associated with consumer use. EPA may identify additional potentially exposed or susceptible subpopulations that it will consider based on greater exposure.
EPA expects to consider hazards of NMP to terrestrial organisms including aquatic plants, birds and mammals exposed under acute and chronic exposure conditions. Based on reasonably available information, EPA will focus its analysis on the hazards of acute toxicity and reproductive / developmental toxicity. The plan includes analysis of environmental releases, environmental fate, environmental exposures, occupational exposures, consumer exposures and general exposures.
EPA will evaluate environmental exposures. EPA expects to consider three broad categories of human exposures: occupational exposures, consumer exposures, and general population exposures. Subpopulations within these exposure categories will also be considered.
EPA will evaluate for liver toxicity, neurotoxicity and irritation. In prior assessments EPA concluded that methylene chloride is likely to be carcinogenic by all routes of exposure.
HBCD (Cyclic Aliphatic Bromide Cluster)
EPA expects to consider exposures to the environment and ecological receptors. EPA expects to consider three broad categories of human exposures: occupational exposures, consumer exposures and general population exposures. Subpopulations within these exposure categories will also be considered as described herein. EPA expects to consider worker activities where there is a potential for exposure.
EPA expects to consider hazards of HBCD to aquatic and terrestrial organisms. Regarding non-cancer health hazards, EPA will evaluate acute toxicity, liver toxicity, thyroid toxicity, reproductive/developmental toxicity, neurotoxicity, immunotoxicity, sensitization, and irritation. Unless new information indicates potential as a carcinogen, EPA does not expect to conduct additional in-depth analysis of genotoxicity or cancer hazards in the risk evaluation of HBCD, due to prior studies failing to demonstrate a hazard.
EPA expects to consider exposures to the environment and ecological receptors. EPA expects to consider three broad categories of human exposures: occupational exposures, consumer exposures, and general population exposures. Wastewater/liquid wastes, solid wastes or air emissions of carbon tetrachloride could result in potential pathways for oral, dermal or inhalation exposure to the general population. EPA will consider each media, route and pathway to estimate general population exposures.
Associated hazards include: acute toxicity (acute lethality at high concentrations only), blood toxicity, immunotoxicity, cardiovascular toxicity, liver toxicity, kidney toxicity, reproductive toxicity, developmental toxicity, and neurotoxicity.
1,4 – Dioxane
Associated hazards include: acute toxicity, irritation, liver toxicity and kidney toxicity.
Associated hazards include: acute toxicity, liver toxicity, kidney toxicity, reproductive /developmental toxicity, neurotoxicity, immunotoxicity and sensitization.
Perchloroethylene (a.k.a. Tetrachloroethylene)
Associated hazards include: acute toxicity, neurotoxicity, kidney toxicity, liver toxicity, reproductive / developmental toxicity and irritation.
Pigment Violet 29 (PV-29)
Regarding environmental hazards, EPA expects to evaluate acute hazards to aquatic and terrestrial organisms. Existing information available from the European Chemicals Agency (ECHA) does not identify environmental hazards. Regarding health hazards, EPA is obtaining existing studies from ECHA and other sources related to acute toxicity (oral/inhalation), skin and eye irritation, in vivo skin sensitization, in vitro genotoxicity, and reproductive/developmental toxicity. EPA will not conduct in-depth analysis of genotoxicity or cancer hazards in the risk evaluation of Pigment Violet 29, due to structure-activity evaluation and genotoxicity studies that do not indicate cancer.