Draft Risk Evaluation under the Toxic Substances Control Act: 1,2-Dichloropropane

1,2-Dichloropropane Draft Risk Evaluation Under the Toxic Substances Control Act (TSCA); Notice of Availability and Request for Comment

DATES:

Comments must be received on or before November 3, 2026.

SUPPLEMENTARY INFORMATION:

I. Executive Summary

A. Does this action apply to me?

This action is directed to the public in general and may be of particular interest to those involved in the manufacture (defined under TSCA section 3(9) to include import), processing, distribution, use, and disposal of 1,2-dichloropropane, related industry trade organizations, non-governmental organizations with an interest in human and environmental health, State and local governments, Tribal Nations, and/or those interested in the assessment of risks involving chemical substances and mixtures regulated under TSCA. As such, the Agency has not attempted to describe all the specific entities that this action might apply to. If you need help determining applicability, consult the relevant technical contact listed under FOR FURTHER INFORMATION CONTACT .

B. What is the Agency's authority for taking this action?

The Agency is conducting this risk evaluation under TSCA section 6, (15 U.S.C. 2605) which requires that EPA conduct risk evaluations on chemical substances and identifies the minimum components EPA must include in the risk evaluations. Each risk evaluation must be conducted consistent with the best available science, be based on the weight of the scientific evidence, consider reasonably available information, and not consider costs or non-risk factors (15 U.S.C. 2625(h), (i), and (k)). See also the implementing procedural regulations at 40 CFR part 702.

C. What action is the Agency taking?

EPA is announcing the availability of and seeking public comment on the draft risk evaluation under TSCA for 1,2-dichloropropane. EPA used the best available science to prepare this draft risk evaluation and preliminarily determined, based on the weight of scientific evidence, that 1,2-dichloropropane does pose unreasonable risk to human health driven primarily by certain COUs analyzed in the draft risk evaluation.

D. What should I consider as I submit my comments to EPA?

1. Submitting CBI

Do not submit CBI through https://www.regulations.gov or email. If you wish to include CBI in your comment, please follow the applicable instructions at https://www.epa.gov/dockets/commenting-epa-dockets#rules and clearly mark the information that you claim to be CBI. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR parts 2 and 703, as applicable.

2. Tips for Preparing Comments

When preparing and submitting your comments, see the commenting tips at https://www.epa.gov/dockets/commenting-epa-dockets.

II. Background for 1,2-Dichloropropane

A. What is 1,2-Dichloropropane?

1,2-Dichloropropane is a volatile, colorless liquid under normal (ambient) conditions with a sweet chloroform-like odor. It is manufactured primarily as a byproduct. Manufacturers, based on the 2024 Chemical Data Reporting (U.S. EPA, 2026, 13246149; available at https://hero.epa.gov/reference/13246149/ ), report the national aggregate production volume of 1,2-dichloropropane is between 100 and 250 million pounds. 1,2- Dichloropropane may also be imported. Industrial and commercial uses of 1,2-dichloropropane include processing (as a reactant), laboratory chemical use, and cleaning and furnishing care products. Workers and occupational non-users (ONUs) may be exposed to 1,2-dichloropropane through the inhalation route and workers may also be exposed through the dermal route associated with manufacturing, processing, use, or disposal of 1,2-dichloropropane and products containing 1,2-dichloropropane. Consumers may be exposed to 1,2-dichloropropane through the dermal and inhalation routes during the intended use of products containing 1,2-dichloropropane. Although volatile, 1,2-dichloropropane is soluble in water and is miscible in most organic solvents. 1,2-Dichloropropane is persistent in the environment and slowly degrades over months to years if released to air, water, soil, and sediment. Environmental releases to air, water, and land occur from industrial and waste handling facilities.

B. The Risk Evaluation of 1,2-Dichloropropane

In December 2019, EPA announced its designation of 1,2-dichloropropane (Docket ID: EPA-HQ-OPPT-2018-0428) as a high-priority substance for risk evaluation under TSCA (84 FR 71924 (FRL-10003-15-OCSPP)). In April 2020, EPA published and sought public comment on the draft scope of the 1,2-dichloropropane risk evaluation (85 FR 19941 (FRL-10007-11-OCSPP)), and, after considering public comments, issued the final scope on September 4, 2020 (85 FR 55281 (FRL-10013-90-OCSPP)). In June 2026, EPA released the draft human health and environmental hazard assessment for public comment and external peer review by the Science Advisory Committee on Chemicals (SACC). As part of the SACC deliberations, the Agency held a virtual public meeting to discuss the draft human health and environmental hazard assessment in August 2026. For more information about this meeting, go to the SACC website at https://www.epa.gov/tsca-peer-review/science-advisory-committee-chemicals-meetings. In July 2026, EPA also released the draft chemistry, fate, release, and exposure assessment for 1,2-dichloropropane.

In this draft risk evaluation, EPA assessed human health risk to workers (including ONUs), consumers, and the general population (including fenceline communities and potentially exposed susceptible subpopulations (PESS)) exposed to environmental releases of 1,2-dichloropropane. Specifically, EPA evaluated acute, intermediate, and chronic non-cancer and cancer risks to workers and ONUs; acute and chronic non-cancer risks to consumers; and acute and chronic non-cancer and cancer risks to the general population (including fenceline communities and PESS). This draft risk evaluation also assessed acute and chronic risks to the environment, specifically to aquatic and terrestrial species.

C. Request for Comment

EPA seeks feedback on the assessment of risk presented in the draft risk evaluation for 1,2-dichloropropane, a copy of which is available in the docket, and encourages all potentially interested parties, including individuals, governmental and non-governmental organizations, non-profit organizations, academic institutions, research institutions, and private sector entities to comment on the draft risk evaluation. To the extent possible, the Agency asks commenters to please cite any public data related to or that support comments provided, and to the extent permissible, describe any supporting data that are not publicly available.

EPA welcomes specific input on each section of the draft risk evaluation, and is particularly interested in:

• Information on whether 1,2-dichloropropane is manufactured as a primary product, or by other manufacturing processes not discussed in this assessment.
• Information on how 1,2-dichloropropane may be distributed for use as a laboratory chemical and in cleaning and furnishing care products.
• Information on the amounts of 1,2-dichloropropane used by commercial laboratories (occupational exposure scenario (OES) #5) on a daily (kg/site-day) and yearly (kg/site-yr) basis and corresponding personal protective equipment (PPE) and engineering controls to reduce exposures.
• Information on the use of 1,2-dichloropropane in all-purpose liquid cleaner/polish or waxes and polishes-particularly for stone polishing and cleaning-including any information supporting this use as a reasonably foreseen use and any information regarding the use being reestablished in the United States. Information may include (1) the potential for 1,2-dichloropropane to be utilized in stone waxes, polishes, and cleaners, including but not limited to information on technological or economic factors that indicate this chemical may or may not be utilized in this type of product going forward; (2) any information on application of these products including method of application, settings, surface area treated and amounts applied; and (3) inhalation and dermal exposure measurements or alternative modeling approaches that would inform EPA's assessment of the commercial and consumer scenarios.
• Information to inform and refine the occupational exposure assessment, including monitoring data, worker activities, concentration of 1,2-dichloropropane as it arrives at sites for these OESs and information on exposure controls and PPE, in particular for the following OESs: Import/Processing-Repackaging (OES #2), Processing Aid (OES #4), Disposal to Incineration (OES #7), Disposal to Landfill (OES #8), and Disposal to publicly owned treatment works (POTW) and Non-POTW wastewater treatment (WWT) (OES #9, #10).

• Information to inform whether the inhalation monitoring data from manufacturing/processing facilities that was used to evaluate occupational exposures for Disposal to Incineration (OES #7), Disposal to POTW/Non-POTW WWT (OES #9 and 10), and Remediation (OES #11) is representative of these OESs-including information on worker activities ( e.g., typical working hours/day and days/year, and personal protective equipment [PPE] use), concentrations of 1,2-dichloropropane in waste streams, and other inhalation monitoring data that could be utilized to assess exposures for these OESs.

• Information that can be used to inform or refine interpretation of occupational exposure estimates for similar exposure groups (SEGs) with large variation in occupational exposure concentrations ( e.g., the marine logistics technician SEG evaluated under the Processing as a Reactant (OES #3)).

• Information on exposure controls and PPE used for each of the COUs, including information on the use of gloves. Specifically, EPA seeks information on prevalence of glove and respirator use, specific tasks for which each is used, glove material, and information on dermal protection programs.

• Information on the effectiveness of glove types for preventing exposures from 1,2-dichloropropane in the context of tasks performed under the COUs-including how workers and their exposure may be affected when using chemically resistant gloves, measured permeation testing of certain types of gloves, and temperature considerations (as identified in the Hand Protection section of the Occupational Safety and Health Administration (OSHA)'s Personal Protective Equipment Guidance and in alignment with the OSHA Hand Protection PPE Standard (29 CFR 1910.138)).

• Other information on any relevant studies or other data sources that were not identified by EPA.

III. Next Steps

After consideration of comments received from the public on the draft risk evaluation and input from the Scientific Advisory Committee on Chemicals (SACC) peer review, EPA will issue the final risk evaluation for 1,2-dichloropropane. Under TSCA section 6, EPA must use the final risk evaluation as a basis to determine, based on the weight of scientific evidence, whether or not the chemical presents an unreasonable risk to human health or the environment under the chemical's COUs. This includes risks to subpopulations who may be at greater risks than the general population, such as children and workers. TSCA prohibits EPA from considering non-risk factors ( e.g., costs/benefits) during risk evaluation.

For more information about the TSCA risk evaluation process for existing chemicals, go to https://www.epa.gov/assessing-and-managing-chemicals-under-tsca.

(Authority: 15 U.S.C. 2601 et seq. )