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August 14, 2019

EPA Proposes to Designate 20 Chemical Substances as Low-Priority Substances

Bergeson & Campbell, P.C.

On August 13, 2019, the U.S. Environmental Protection Agency (EPA) released the list of 20 chemical substances that it proposes to designate as low-priority substances for which risk evaluation under the Toxic Substances Control Act (TSCA) is not warranted at this time. The pre-publication version of EPA’s proposed rule provides a summary of the approach used by EPA to support the proposed designations, the proposed designations for each of the chemical substances, and instructions on how to access the chemical-specific information, analysis, and basis used by EPA to make the proposed designation for each chemical substance. EPA published its Approach Document for Screening Hazard Information for Low-Priority Substances Under TSCA (Approach Document), which describes the literature review process for the information used in the screening review for each proposed low-priority chemical substance. Publication of the proposed rule in the Federal Register will begin a 90-day comment period on the proposed designations and on EPA’s Approach Document.

As reported in our March 22, 2019, memorandum, “EPA Releases List of 40 Chemicals Undergoing Prioritization for Risk Evaluation,” EPA released in March 2019 a list of 40 chemicals for which it initiated the prioritization process for risk evaluation. EPA selected 20 chemical substances as candidates for designation as low-priority substances and now proposes to designate the same 20 chemical substances as low-priority substances:

Chemical NameDocket Number
1-Butanol, 3-methoxy-, 1-acetateEPA-HQ-OPPT-2019-0106
D-gluco-Heptonic acid, sodium salt (1:1), (2.xi.)-EPA-HQ-OPPT-2019-0107
D-Gluconic acidEPA-HQ-OPPT-2019-0108
D-Gluconic acid, calcium salt (2:1)EPA-HQ-OPPT-2019-0109
D-Gluconic acid, .delta.-lactoneEPA-HQ-OPPT-2019-0110
D-Gluconic acid, potassium salt (1:1)EPA-HQ-OPPT-2019-0111
D-Gluconic acid, sodium salt (1:1)EPA-HQ-OPPT-2019-0112
Decanedioic acid, 1,10-dibutyl esterEPA-HQ-OPPT-2019-0113
Propanol, [2-(2-butoxymethylethoxy)methylethoxy]-EPA-HQ-OPPT-2019-0118
Propanedioic acid, 1,3-diethyl esterEPA-HQ-OPPT-2019-0119
Propanedioic acid, 1,3-dimethyl esterEPA-HQ-OPPT-2019-0120
Propanol, 1(or 2)-(2-methoxymethylethoxy)-, acetateEPA-HQ-OPPT-2019-0121
Propanol, [(1-methyl-1,2-ethanediyl)bis(oxy)]bis-EPA-HQ-OPPT-2019-0122
2-Propanol, 1,1′-oxybis-EPA-HQ-OPPT-2019-0123
Propanol, oxybis-EPA-HQ-OPPT-2019-0124
Tetracosane, 2,6,10,15,19,23-hexamethyl-EPA-HQ-OPPT-2019-0125

The supporting materials for the 20 proposed low-priority chemical substances will be available for comment in their respective dockets upon publication in the Federal Register. EPA has also posted the supporting materials on its website.

EPA states that it generally used reasonably available information to screen the candidate chemical substances against the following criteria and considerations:

  • The chemical substance’s hazard and exposure potential;
  • The chemical substance’s persistence and bioaccumulation;
  • Potentially exposed or susceptible subpopulations;
  • Storage of the chemical substance near significant sources of drinking water;
  • The chemical substance’s conditions of use or significant changes in conditions of use;
  • The chemical substance’s production volume or significant changes in production volume; and
  • Other risk-based criteria that EPA determines to be relevant to the designation of the chemical substance’s priority for risk evaluation.

In conducting the screening review during the prioritization process, EPA states that it considered sources of information relevant to the screening-review criteria as outlined in TSCA Section 6(b)(l)(A) and 40 C.F.R. Section 702.9(a) and consistent with the scientific standards of TSCA Section 26(h). EPA collected and evaluated all hazard and fate information for the proposed low-priority substances in accordance with the methodology laid out in the Approach Document. In addition, EPA considered the hazard and exposure potential of the chemical substances and states that it did not consider cost or other non-risk factors in making the proposed priority designations.


As expected, EPA has formally proposed as low-priority substances the 20 substances that EPA proposed in March as potential low-priority substances. Stakeholders will have 90 days to comment on whether EPA has met the statutory obligation to have information “sufficient to establish” that the substances do not meet the standard for high-priority substances (that the substances may present an unreasonable risk). Comments were filed on only seven of the 20 substances initially identified as low priority, and all comments supported the designations as low priority.