The U.S. Environmental Protection Agency announced on June 17, 2026, that it is advancing its review of five chemicals under the Toxic Substances Control Act.
The five chemicals under review are 1,1,2-trichloroethane, TBBPA, 1,2-dichloropropane, ethylene dibromide, and trans-1,2-dichloroethylene.
EPA is sending the underlying science to the Science Advisory Committee on Chemicals for peer review and opening the process for public comment.
The agency stated that “these chemicals appear in flame retardants, cleaning and degreasing products, leaded aviation gasoline, laboratories, and industrial processes.”
EPA added that its conclusions “can directly affect the air Americans breathe at home, at work, and in their communities.”
Technical support documents for four of the five chemicals were released on June 17, 2026, with the TBBPA draft risk evaluation having been published five days earlier on June 12.
Draft documents for all five chemicals are available in peer review docket EPA-HQ-OPPT-2026-2246 at www.regulations.gov for public comment and independent scientific peer review.
Ethylene dibromide is used mainly as a lead scavenger in leaded aviation gasoline, prompting EPA to examine it “in the broader context of lead exposure, including around airports and in communities near where it is handled.”
For 1,1,2-trichloroethane, EPA’s draft materials highlight respiratory, immune, neurological, and liver effects as key non-cancer concerns, alongside evidence of carcinogenicity and risks to aquatic and terrestrial species.
EPA states it “is paying particular attention to the people most at risk — workers with the heaviest exposures, pregnant women, children, and communities living near sources.”
A virtual public meeting of the Science Advisory Committee on Chemicals is scheduled for August 3-7, 2026, to review the draft technical support documents for all five chemicals.
A preparatory virtual public meeting will be held on July 23, 2026, allowing the committee and the public to ask questions about the scope of the draft charge questions.
EPA will release draft risk evaluations for the remaining four chemicals prior to the August peer review meeting, anticipating no need for additional peer review of those forthcoming documents.
The agency’s decision to submit only component parts of the risk evaluations for peer review has drawn criticism, with many arguing it risks undermining the completeness of independent scientific scrutiny.
Observers have noted that relegating peer review to individual technical documents, rather than full risk evaluations, may shield EPA from scrutiny on what one analysis calls “the more consequential analytical leaps.”
EPA has countered that scientific methodologies already vetted by the committee should not require re-examination each time they are applied to a new chemical substance.
The question of whether applying established methods to specific chemicals constitutes a scientific judgment that itself warrants independent review remains a matter of ongoing debate within the regulated community.