EPA Finds Unreasonable Risk in Four Draft TSCA Risk Evaluations
In August and early September, EPA released draft risk evaluations for 1,2-dichloropropane, trans-1,2-dichloroethylene, o-dichlorobenzene (oDCB), and p-dichlorobenzene (pDCB) under the Toxic Substances Control Act (TSCA). EPA preliminarily determined that all four substances present unreasonable risk, driven primarily by certain conditions of use analyzed in the draft risk evaluations.
EPA will consider public comments before finalizing the evaluations. If EPA continues to find unreasonable risk, the agency will propose risk management actions under TSCA Section 6(a) to address those exposures.
1,2-Dichloropropane
1,2-Dichloropropane is an industrial chemical used in laboratory and industrial applications. According to EPA, it was previously used in cleaners, polishes, and waxes, and the Agency is evaluating those uses because imported products may still contain the substance. EPA has recognized 1,2-dichloropropane as likely to be carcinogenic to humans.
EPA’s draft evaluation identifies significant contributions to unreasonable risk to workers and occupational non-users from inhalation and dermal exposure under 11 conditions of use. Three consumer uses involving cleaners, polishes, and waxes were also preliminarily found to contribute to unreasonable risk. EPA did not identify unreasonable risk to the general population or the environment.
trans-1,2-Dichloroethylene
trans-1,2-Dichloroethylene is used in industrial and commercial cleaning and degreasing, as a processing aid, and in consumer products such as cleaners, degreasers, and foam insulation.
EPA’s draft evaluation identifies significant contributions to unreasonable risk to workers and occupational non-users from inhalation exposure under 19 conditions of use. One consumer use of trans-1,2-dichloroethylene—as a cleaner or degreaser—was also preliminarily found to contribute to unreasonable risk. EPA did not identify unreasonable risk to the general population or the environment.
oDCB and pDCB
oDCB and pDCB are used in household and commercial products and can evaporate into the air. pDCB is used in some air-care and deodorizing products, making indoor air a potential route of consumer exposure.
EPA’s draft evaluation for oDCB identifies contributions to unreasonable risk to workers from 14 conditions of use through inhalation, with dermal exposure contributing to risk in seven conditions of use. The draft also identifies unreasonable risk to consumers from one condition of use through inhalation.
For pDCB, EPA identified contributions to unreasonable risk to workers from seven conditions of use through inhalation and dermal exposure, as well as to consumers through inhalation from air-care products.
For both substances, EPA evaluated developmental, liver, and respiratory toxicity. EPA’s worker risk estimates do not assume the use of personal protective equipment (PPE), although the draft evaluations separately discuss how PPE and other controls could reduce exposure. EPA did not identify unreasonable risk to the general population through ambient outdoor air, including fenceline communities, or to the environment.
EPA’s draft evaluation for pDCB also concludes that the substance is not likely to be carcinogenic to humans. EPA acknowledges, however, that the International Agency for Research on Cancer and the National Toxicology Program have classified pDCB differently. EPA is specifically seeking comments and data on its assessment.
What This Means in the Context of EPA’s TSCA Evaluations
EPA is behind schedule on legally required risk evaluations under TSCA. In November 2024, EPA entered into consent decrees with the D.C. District Court concerning 22 risk evaluations, none of which were completed within TSCA’s 3.5-year deadline. The consent decrees created a court-enforceable schedule for EPA to complete the overdue evaluations.
The consent decrees have since been modified. In March 2025, EPA asked the court to extend by 60 days the deadlines for two draft risk evaluations and the final risk evaluation for 1,1-dichloroethane. The court granted the extensions on March 7, 2025.
The release of these four draft evaluations reflects EPA’s continuing effort to complete years-overdue TSCA risk evaluations under the court-ordered schedule established to address the Agency’s backlog.
