Test Orders Issued for 8 High-Priority Chemicals Under TSCA

A new group of test orders was recently issued by the U.S. Environmental Protection Agency (EPA) for the purpose of acquiring more information on eight of the initial 20 high-priority chemicals undergoing risk evaluations under the Toxic Substances Control Act (TSCA). In this blog post, we examine the nature of TSCA section 4 test orders and review the substances on which the new orders focus.

Test Orders Under TSCA Section 4

The EPA is allowed, via TSCA section 4, to require chemical importers, manufacturers, and processors to develop chemical information and submit such information to the Agency.

  • TSCA Section 4(a)(1)
      • This allows the Agency to issue an order when:
        • sufficient information is not available;
        • testing is required to obtain the information; and
        • unreasonable risk may be caused by the chemical, or significant human or environmental exposures may result given the chemical’s quantity
  • TSCA Section 4(a)(2)
      • This allows the Agency to issue an order to require information development:
        • to review a TSCA section 5-submitted notice or to perform a risk evaluation under TSCA section 6(b);
        • to implement a requirement under TSCA section 5(e) or (f), or in a rule under TSCA section 6(a);
        • when requested by a Federal implementing authority to meet the toxicity and exposure testing needs of that authority;
        • to ascertain whether a chemical designated solely for export presents an unreasonable risk to the environment or human health, relative to section 12(a)(2) of TSCA;
        • to prioritize a chemical under section 6(b) of TSCA

According to the EPA, test orders and the corresponding information they help obtain enable the Agency's risk evaluations to be “robust, credible, and use the best available data.”

High Priority Chemicals

The high-priority chemicals for which the EPA recently issued test orders under section 4 of TSCA are included in the table below. These include six chlorinated solvents and two flame retardants.

Substance NameCAS Registry NumberClassification
1,1,2-Trichloroethane79-00-5Chlorinated Solvent
1,2-Dichloroethane107-06-2Chlorinated Solvent
1,2-Dichloropropane78-87-5Chlorinated Solvent
4,4’-(1-Methylethylidene)bis[2,6-dibromophenol]79-94-7Flame Retardant
o-Dichlorobenzene95-50-1Chlorinated Solvent
p-Dichlorobenzene106-46-7Chlorinated Solvent
Phosphoric acid, Triphenyl Ester115-86-6Flame Retardant
trans-1,2-Dichloroethylene156-60-5Chlorinated Solvent

Source: European Chemicals Agency

The eight substances are among the larger group of twenty chemicals that were designated as high priority for risk evaluation under TSCA in late 2019. This group also included the following:

Substance NameCAS Registry Number
Ethylene dibromide (Ethane, 1,2-dibromo-)106-93-4
1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB)1222-05-5
Tris(2-chloroethyl) phosphate (TCEP) (Ethanol, 2-chloro-, 1,1′,1″-phosphate)115-96-8
Butyl benzyl phthalate (1,2-Benzenedicarboxylic acid, 1- butyl 2-(phenylmethyl) ester)85-68-7
Dibutyl phthalate (1,2-Benzenedicarboxylic acid, 1,2- dibutyl ester)84-74-2
Dicyclohexyl phthalate84-61-7
Phthalic anhydride (1,3-Isobenzofurandione)85-44-9
Di-ethylhexyl phthalate (1,2-Benzenedicarboxylic acid, 1,2- bis(2-ethylhexyl) ester)117-81-7
Di-isobutyl phthalate (1,2-Benzenedicarboxylic acid, 1,2-bis(2-methylpropyl) ester)84-69-5

Source: European Chemicals Agency

The issuance of the test orders for the eight chemical substances represents the third time that the Agency has taken such measures under the amended TSCA (section 4). Orders were previously issued, in January of last year, for these eight chemicals as well as another (1,1-dichloroethane).

Accessing More Information

More information on the recently issued TSCA section 4 test orders, including subsequent corrections to them, may be found on the EPA’s website as it becomes available. Additionally, you can visit the ToxPlanet website and blog regularly for information on new developments. Contact us and register for a Free Trial to see how our powerful decision support solutions can help address your chemical hazard information needs.