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February 25, 2020

EPA Announces Final List of Low-Priority Chemicals under TSCA

Bergeson & Campbell, P.C.

The U.S. Environmental Protection Agency (EPA) announced on February 20, 2020, the final list of 20 chemical substances designated as low-priority substances for which risk evaluation under the Toxic Substances Control Act (TSCA) is not warranted at this time. EPA has posted a pre-publication version of the Federal Register notice. The notice includes the final designation 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 final designation for each chemical substance. EPA notes in its press release that these 20 low-priority chemicals are on its Safer Chemical Ingredients List, “which includes chemicals that meet strict criteria for both human health and the environment.”

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, proposed in August 2019 to designate them as low-priority substances, and has now designated these same 20 chemical substances as low-priority:

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

EPA states that it used “reasonably available information” to screen each candidate chemical substance against the following criteria and considerations and thereby inform the proposed designation:

  • 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.

For the final priority designation, EPA states that it considered comments and information submitted by the public during two public comment periods (after initiation and after proposed designation) and incorporated them as appropriate in preparing the final list of 20 chemical substances designated as low-priority substances. EPA notes that as required by TSCA Section 6(b)(1)(B)(ii) and 40 C.F.R. Section 702.11(b), it did not consider cost or other non-risk factors in making a priority designation.

The initiation of the prioritization process in March 2019 included a 90-day comment period during which interested persons were able to submit relevant information on those chemical substances identified as candidates for low-priority substance designation. According to EPA, during the 90-day comment period, commenters submitted information on four chemical substances identified as candidates for low-priority designation:

  • Propanol, [(1-methyl-1,2-ethanediyl)bis(oxy)]bis-;
  • Propanol, 1(or 2)-(2-methoxymethylethoxy)-, acetate;
  • Propanol, [2-(2-butoxymethylethoxy)methylethoxy]-; and
  • Propanol, oxybis-.

EPA states that it incorporated the chemical-specific information submitted during the initiation public comment period in the screening reviews published at proposal. EPA also received general prioritization comments during the initiation public comment period, as summarized in the notice. The notice includes a high-level synopsis of comments received during the initiation stage, and EPA’s responses to those comments.

The proposed designation stage of the prioritization process that began in August 2019 included a 90-day comment period during which interested persons were able to submit relevant information on the chemical substances proposed for low-priority substance designation. EPA states that it 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 for Screening Hazard Information for Low-Priority Substances Under TSCA (Approach Document). EPA included information gathered according to the Approach Document in each chemical substance’s screening review. EPA considered the information submitted during the screening review and the proposed priority designation public comment period for specific chemical substances, as appropriate, in making the final low-priority substance designations. According to the notice, during the public comment period for the proposed designation stage, EPA received 11 submissions from eight different entities, including environmental and health advocacy groups, a trade association, an academic institution, and anonymous commenters. The notice includes a high-level synopsis of comments received during the proposed designation stage, and EPA’s responses to those comments.

Once EPA publishes the final list in the Federal Register, it will add supporting documents for each chemical substance to its docket. The support document will include the information, analysis, and basis used to support each chemical substance’s final designation as a low-priority substance. In the absence of experimental data for a given endpoint, EPA states that it integrated information using New Approach Methodologies (NAM).


We congratulate EPA for completing another of the actions required by amended TSCA, albeit somewhat (although understandably) late. We note EPA’s use of careful wording and the relatively comprehensive discussion of comments and EPA responses in the notice as well as the frequent references to its underlying screening reviews. These seem intended to forestall a legal challenge and to provide an affirmative defense in the key documents in the event of a challenge. Regardless, the devil is in the details of the screening review dossiers as well as EPA’s scientific, legal, and policy decisions regarding prioritization made over the course of the past three and one-half years. It remains to be seen if any parties will choose to challenge whether EPA’s determinations were “sufficient to establish” that one or more chemicals do not warrant high-priority designation.

Another aspect to watch relates to concerns the precedents established and the specific language EPA uses in this first round of low-priority designations and how those precedents and EPA verbiage will fare in helping or complicating EPA efforts to make the case for future low-priority designations and in designating as high-priority chemicals that merit risk evaluation. In particular, we note EPA’s use of the term “consistently low hazard characteristics” to describe a key aspect of these chemicals and EPA’s approach. While we recognize that a hazard-based approach provides a simple starting point for EPA to establish the first low-priority substances, we have concerns that EPA might limit future low-priority designations to low-hazard substances. The statute clearly uses the term “risk-based screening process,” not in a strictly hazard-based approach to prioritization. We had identified this concern in the development of the legislation and encourage EPA to work to expand the envelope of low-priority chemicals beyond those that are per se low hazard and, correspondingly, to limit the envelope of high-priority chemicals. Absent such efforts, EPA will have too many risk evaluations in its future and perhaps, more ominously, could contribute to the public concluding that only no-hazard chemicals are acceptable.