EPA draft trans-1,2-dichloroethylene evaluation finds unreasonable worker risk

EPA trans-1,2-dichloroethylene risk evaluation identifies workplace concerns

Trans-1,2-dichloroethylene, often abbreviated to trans-DCE, is a volatile chlorinated solvent used as a cleaner and degreaser, processing aid, reaction product, surface modifier and in other industrial applications. EPA evaluated inhalation and dermal exposures, releases from industrial and commercial activities and risks across the chemical's lifecycle.

The agency's preliminary unreasonable-risk conclusion is driven by particular conditions of use rather than every use of trans-DCE. The draft therefore does not amount to a general ban, a new occupational exposure limit or an immediate restriction. It is the scientific and legal assessment that may support a later risk-management rule.

EPA is particularly seeking information on personal protective equipment, use as a blowing agent, vapour-degreasing operations, manufacture as a by-product, batch frequency and semiconductor formulations. Businesses with representative monitoring, process and control data should assess whether the assumptions reflect actual operations.

What changed and what remains unchanged

The new trigger is the publication of the complete draft evaluation and preliminary risk determination. Foresight previously covered EPA's June peer-review plans for five high-priority chemicals, including trans-DCE. This notice advances that process by exposing EPA's full analysis and opening a formal comment period.

Current TSCA duties, hazard communication requirements and applicable workplace controls remain unchanged. EPA must review comments and peer-review input before issuing a final evaluation. If the agency finalises an unreasonable-risk finding, TSCA then requires a separate risk-management process in which EPA can propose controls for the contributing conditions of use.

Implications across the trans-DCE value chain

Manufacturers and importers should trace volumes and downstream uses, while formulators and distributors should confirm that exposure information follows the product. Industrial users should compare EPA's scenarios with ventilation, enclosure, respiratory protection and dermal controls. Waste operators should review handling and release assumptions for residues and spent solvent.

Inference: the targeted data requests indicate where uncertainty could most influence EPA's final conclusions. Detailed, quality-assured evidence on exposure frequency, engineering controls and protective-equipment performance is therefore likely to be more useful than broad assertions that operations are safe.

Practical stakeholder actions

Identify all trans-DCE uses and suppliers, download the draft and supporting files, and map each relevant condition of use to site evidence. Validate exposure measurements, personal protective equipment programmes, release estimates and waste routes. Where the record is incomplete or materially unrepresentative, prepare a source-referenced submission to docket EPA-HQ-OPPT-2018-0465 by 26 October 2026.