EPA Announces Availability of Final Scope Documents for TSCA Risk Evaluations
The U.S. Environmental Protection Agency (EPA) published a notice on September 4, 2020 announcing final scope document availability for 20 chemicals. These represent the first group of substances deemed, in December 2019, as being high priority for risk evaluation under the Toxic Substances Control Act (TSCA). In this blog post, we review these chemicals and look at the makeup of the corresponding documents.
During the process of risk evaluation, the EPA uses information aligning with TSCA requirements. The Agency is required to meet TSCA’s criteria for best available science and uses a “weight-of-scientific-evidence” methodology. The ultimate goal of the process is to ascertain whether a chemical poses an unreasonable risk to health or to the environment under its use conditions.
20 High Priority Chemicals
The 20 chemicals previously designated by the EPA as high-priority substances for the purpose of risk evaluation under TSCA are listed in the table below.
|Substance Name||CAS Registry Number||Chemical Group|
|o-Dichlorobenzene (Benzene, 1,2-dichloro-)||95-50-1||N/A|
|p-Dichlorobenzene (Benzene, 1,4-dichloro-)||106-46-7||N/A|
|trans-1,2-Dichloroethylene (Ethene, 1,2-dichloro-, (1E)-)||156-60-5||Solvent|
|Ethylene dibromide (Ethane, 1,2-dibromo-)||106-93-4||N/A|
|1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB)||1222-05-5||Fragrance Additive|
|4,4′-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA)||79-94-7||Flame Retardant|
|Phosphoric acid, triphenyl ester (TPP)||115-86-6||Flame Retardant|
|Tris(2-chloroethyl) phosphate (TCEP) (Ethanol, 2-chloro-, 1,1′,1″-phosphate)||115-96-8||Flame Retardant|
|Butyl benzyl phthalate (1,2-Benzenedicarboxylic acid, 1- butyl 2-(phenylmethyl) ester)||85-68-7||Phthalate|
|Dibutyl phthalate (1,2-Benzenedicarboxylic acid, 1,2- dibutyl ester)||84-74-2||Phthalate|
|Phthalic anhydride (1,3-Isobenzofurandione)||85-44-97||N/A|
|Di-ethylhexyl phthalate (1,2-Benzenedicarboxylic acid, 1,2- bis(2-ethylhexyl) ester)||117-81-7||Phthalate|
|Di-isobutyl phthalate (1,2-Benzenedicarboxylic acid, 1,2-bis(2-methylpropyl) ester)||84-69-5||Phthalate|
Source: U.S. Environmental Protection Agency
Key Scope Document Components
The final scope documents for the prioritized chemical substances each contain several key components:
- A description of the use conditions the EPA intends review in its risk evaluations.
- A review of the potentially exposed groups, and the environmental and health hazards, that the EPA intends to consider.
- A description of the approaches and information the EPA intends to use.
- A conceptual model focused on the relationships between chemical substance, conditions of use, and more.
- A plan for analysis identifying the EPA’s intended methods for evaluating hazards, exposure, risks, etc.
- A peer review plan.
Finalization of the documents was shaped by public feedback and comments received on the previous corresponding draft scope documents.
To Learn More
To learn more about the availability of the EPA’s final scope documents regarding the 20 high-priority chemical substances, read the notice published in the Federal Register.