The Environmental Protection Agency said on September 4 that a draft evaluation has preliminarily determined that 1,2-dichloropropane poses an unreasonable risk to human health, driven primarily by certain conditions of use. The word preliminarily is doing real work here. This is a draft document opened for public comment, not a final determination, and it imposes no restriction on any use of the chemical.

Under the Toxic Substances Control Act, a draft evaluation of this kind is the step before a final risk determination. If the finding holds after public comment and outside peer review, the law then requires the agency to move to a separate risk management stage where restrictions could be proposed. That stage has not begun.

The chemical is not a household name, and for most readers it is not something encountered directly. Its relevance runs through workplaces, industrial releases and the communities that sit near facilities handling it. Comments must be received on or before November 3, 2026.

The Chemical, Its Volume and Its Behavior in the Environment

1,2-Dichloropropane is a volatile, colorless liquid with a sweet, chloroform-like odor. According to the notice in the Federal Register, manufacturers reported a national aggregate production volume of between 100 and 250 million pounds in 2024 chemical data reporting, and the chemical is manufactured primarily as a byproduct rather than as a target product. It may also be imported.

Industrial and commercial uses named by the agency include processing as a reactant, laboratory chemical use, and cleaning and furnishing care products. The agency has asked specifically whether the chemical is still used in stone waxes, polishes and cleaners, or whether that use could be reestablished in the United States, which signals genuine uncertainty about part of the exposure picture.

Persistence is the environmental detail that matters most. The agency describes the chemical as persistent, degrading slowly over months to years when released to air, water, soil or sediment. It is soluble in water and miscible in most organic solvents, and the agency notes that environmental releases to air, water and land occur from industrial and waste handling facilities.

Workers and Nearby Communities Carry the Modeled Exposure

The draft assessed several populations separately. The agency evaluated acute, intermediate and chronic non-cancer risks and cancer risks for workers and for occupational non-users, meaning employees who work near a process without handling the chemical. It assessed acute and chronic non-cancer risks for consumers, and acute and chronic non-cancer and cancer risks for the general population, a category the agency defined to include fenceline communities and potentially exposed or susceptible subpopulations.

Exposure routes differ by group. Workers and occupational non-users may be exposed by inhalation, and workers may also be exposed through skin contact during manufacturing, processing, use or disposal. Consumers may be exposed through skin contact and inhalation while using products that contain the chemical. The agency also evaluated acute and chronic risks to aquatic and terrestrial species.

The agency said it preliminarily determined, based on the weight of scientific evidence, that the chemical does pose an unreasonable risk to human health, driven primarily by certain conditions of use. It did not identify a single dominant exposure scenario in the notice, and the specific drivers are detailed in the draft document itself rather than the announcement.

This is the agency's preliminary position, and no independent toxicological review of the draft has been published alongside it. The draft is subject to change through peer review by the Science Advisory Committee on Chemicals, which held a virtual public meeting in August to discuss the underlying hazard assessment.

Gaps the Agency Says It Cannot Fill on Its Own

The request for comment is unusually specific about what is missing, which is a useful signal about the strength of the current analysis. The agency asked for information on whether the chemical is ever manufactured as a primary product rather than a byproduct, how it reaches laboratories and cleaning products, and how much commercial laboratories use on a daily and yearly basis.

It also sought monitoring data and details on protective equipment for several occupational scenarios, including repackaging, processing aid use, disposal to incineration, disposal to landfill, and disposal to publicly owned and non-public wastewater treatment. For incineration, wastewater treatment, and remediation, the agency used inhalation monitoring data collected at manufacturing and processing facilities as a stand-in, and it is asking whether that substitution is defensible.

Glove use drew particular attention. The agency requested data on how often gloves and respirators are worn, what materials are used, and how effective specific glove types are at blocking this chemical during real tasks. Those are the kinds of questions that determine whether a modeled worker exposure reflects a real one.

That level of acknowledged uncertainty is the reason to read the finding carefully rather than as a settled conclusion. It also means comments from workers, industrial hygienists, laboratory managers, and local health departments can change the analysis in ways that general opposition or support cannot.

From Draft Evaluation to a Possible Final Determination

Anyone can submit comments through regulations.gov under the chemical's docket, EPA-HQ-OPPT-2018-0428. The agency says confidential business information should not be submitted through the portal or by email, and its docket guidance explains how to mark and handle it. Personal details included in a comment may be posted publicly.

The chemical has been in the queue for a long time. The agency designated it a high-priority substance in December 2019, published a draft scope in April 2020 and a final scope in September, released the draft hazard assessment in June 2026, and released the draft chemistry, fate, release and exposure assessment in July 2026. The notice was signed by Douglas M. Troutman, assistant administrator for the Office of Chemical Safety and Pollution Prevention.

Several things remain unknown. The agency has not said when the final evaluation will be issued, has not proposed any restriction, and has not stated which conditions of use would be targeted if the finding is confirmed. Under the statute, the agency is barred from weighing costs and other non-risk factors at the evaluation stage. More detail on that sequence is available through the agency's existing chemicals program.

For most households, no action is warranted today. Workers who handle solvents in laboratories, repackaging operations or waste treatment, and residents near facilities that report releases have the strongest reason to read the draft and to file comment before the November deadline.

What Readers Want to Know

Is this a final decision that the chemical is dangerous?

No. It is a draft risk evaluation with a preliminary determination. The agency must consider public comment and outside peer review before issuing a final evaluation.

Does anything change for consumers right now?

No. The announcement imposes no restriction, recall or advisory. Any restriction would come later, through a separate risk management process that has not started.

Who faces the most exposure?

The agency assessed workers and occupational non-users, consumers using products containing the chemical, and the general population including fenceline communities. Workers may be exposed through both inhalation and skin contact.

How much of this chemical is produced?

Manufacturers reported a national aggregate production volume between 100 and 250 million pounds, based on 2024 chemical data reporting. It is manufactured mostly as a byproduct.

How long does it last in the environment?

The agency describes it as persistent, degrading slowly over months to years when released to air, water, soil or sediment.

When and how can the public comment?

Comments must be received on or before November 3, 2026, through regulations.gov under docket ID EPA-HQ-OPPT-2018-0428. Confidential business information should not be submitted through the portal or by email.

What happens after the comment period closes?

The agency will consider comments and peer review input, then issue a final risk evaluation. Only after that can it determine whether to pursue restrictions.