Environmental Protection Agency to Evaluate 40 Substances Under the Toxic Substances Control Act

Environmental Protection Agency to Evaluate 40 Substances Under the Toxic Substances Control Act

On March 20, 2019, the U.S. Environmental Protection Agency (EPA) outlined 40 substances to undergo the evaluation and prioritization process outlined by the amended Toxic Substances Control Act (TSCA). Twenty high-priority substances will receive a 90-day public consultation, with another period of consultation for 20 low-priority substances to follow. The public comment period is an opportunity for relevant parties to submit information as to the uses and hazards of these chemicals, as well as potential exposures.

A high-priority designation will automatically trigger a three-year risk evaluation of the substance, while a low-priority designation means the substance will not be reviewed at this time. The EPA has until December 22, 2019, to complete the designation process.

High-Priority Candidates

A high-priority substance is one that the EPA determines, without taking costs or other non-risk factors into consideration, may present an unreasonable risk of harm to the public, environment and/or vulnerable subpopulations. The agency will also consider potential hazards and route of exposure under the substance’s conditions of use.

The high-priority substances are:

  1. p-Dichlorobenzene — CAS 106-46-7.
  2. 1,2-Dichloroethane — CAS 107-06-2.
  3. trans-1,2- Dichloroethylene — CAS 156-60-5.
  4. o-Dichlorobenzene — CAS 95-50-1.
  5. 1,1,2-Trichloroethane — CAS 79-00-5.
  6. 1,2-Dichloropropane — CAS 78-87-5.
  7. 1,1-Dichloroethane — CAS 75-34-3.
  8. Dibutyl phthalate (DBP) (1,2-Benzene- dicarboxylic acid, 1,2- dibutyl ester) — CAS 84-74-2.
  9. Butyl benzyl phthalate (BBP) (1,2-Benzene- dicarboxylic acid, 1- butyl 2[phenylmethyl] ester) — CAS 85-68-7.
  10. Di-ethylhexyl phthalate (DEHP) (1,2-Benzene- dicarboxylic acid, 1,2- bis[2-ethylhexyl] ester) — CAS 117-81-7.
  11. Di-isobutyl phthalate (DIBP) (1,2-Benzene- dicarboxylic acid, 1,2- bis-[2methylpropyl] ester) — CAS 84-69-5.
  12. Dicyclohexyl phthalate — CAS 84-61-7.
  13. 4,4′-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA) — CAS 79-94-7.
  14. Tris(2-chloroethyl) phosphate (TCEP) — CAS 115-96-8.
  15. Phosphoric acid, triphenyl ester (TPP) — CAS 115-86-6.
  16. Ethylene dibromide — 106-93-4.
  17. 1,3-Butadiene — 106-99-0.
  18. 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB) — CAS 1222-05-5.
  19. Formaldehyde — CAS 50-00-0.
  20. Phthalic anhydride — CAS 85-44-9.

The Low-Priority Candidates

Substances designated as low-priority will not undergo a three-year risk evaluation. However, if during the priority assessment process there is insufficient evidence to formally declare the substance low-priority, it will automatically become high-priority and therefore undergo the risk evaluation.

The low-priority substances are:

  1. 1-Butanol, 3-methoxy-, 1-acetate — CAS 4435-53-4.
  2. D-gluco-Heptonic acid, sodium salt (1:1), (2.xi.)- — CAS 31138-65-5.
  3. D-Gluconic acid — CAS 526-95-4.
  4. D-Gluconic acid, calcium salt (2:1) — CAS 299-28-5.
  5. D-Gluconic acid, .delta.-lactone — CAS 90-80-2.
  6. D-Gluconic acid, potassium salt (1:1) — CAS 299-27-4.
  7. D-Gluconic acid, sodium salt (1:1) — CAS 527-07-1.
  8. Decanedioic acid, 1,10-dibutyl ester — CAS 109-43-3.
  9. 1-Docosanol — CAS 661-19-8.
  10. 1-Eicosanol — CAS 629-96-9.
  11. 1,2-Hexanediol — CAS 6920-22-5.
  12. 1-Octadecanol — CAS 112-92-5.
  13. Propanol, [2-(2-butoxymethylethoxy)methylethoxy]- — CAS 55934-93-5.
  14. Propanedioic acid, 1,3-diethyl ester — CAS 105-53-3.
  15. Propanedioic acid, 1,3-dimethyl ester — CAS 108-59-8.
  16. Propanol, 1(or 2)-(2-methoxymethylethoxy)-, acetate — CAS 88917-22-0.
  17. Propanol, [(1-methyl-1,2-ethanediyl)bis(oxy)]bis- — CAS 24800-44-0.
  18. 2-Propanol, 1,1′-oxybis- — CAS 110-98-5.
  19. Propanol, oxybis- — CAS 25265-71-8.
  20. Tetracosane, 2,6,10,15,19,23-hexamethyl- — CAS 111-01-3.


The inclusion of formaldehyde in the high-priority list has been a cause for concern for some advocacy groups. The substance, widely used in construction and as a preservative, has already been undergoing evaluation by the Integrated Risk Information System (IRIS). The EPA has said the work completed under IRIS will “inform” the evaluation process, but that the work will now continue under the EPA.


All 40 substances are currently available in the U.S. market and can be found in the supply chains of companies across many verticals. Companies that are able to track substances through their supply chains will have an advantage in responding to regulatory changes that may emerge from these evaluations.Assent Compliance streamlines the data collection process, automates supplier engagement, and helps companies proactively respond to a variety of current, expanding and new regulations. Learn more about Assent’s product offerings in our guide, Managing Supply Chain Data With the Assent Compliance Platform. To find out how Assent can help you build a robust, comprehensive product compliance program, contact us at info@assentcompliance.com.