US EPA Finalises Significant New Use Rules For Industrial Chemicals

The US Environmental Protection Agency has finalised significant new use rules under the Toxic Substances Control Act (TSCA) for specified chemical substances. Published on 5 November 2026, the final rule takes effect on 4 January 2027. It covers manufacturers, including importers, and processors undertaking uses designated in the substance-specific provisions.

Notification And Review

A designated significant new use requires notification to EPA at least 90 days before manufacture or processing begins. The activity cannot start until EPA has reviewed the notification, made the relevant determination and taken any action that determination requires. The 90-day notice is therefore not an automatic permission to proceed.

The rule covers substances including multi-walled carbon nanotubes, a fumarated rosin polymer and specified battery-related chemicals. Individual provisions address workplace protection, hazard communication, uses, disposal or releases. The applicable conditions vary by substance; this is not a blanket prohibition on those materials. Final rule, substance-specific provisions.

Earlier Orders And The Cutoff Date

The substances were previously subject to premanufacture notices and EPA orders under TSCA. These rules identify activities departing from the underlying orders’ restrictions as significant new uses. EPA proposed the rules on 5 June 2026 and uses that date as the cutoff for determining whether a use was ongoing.

EPA explains that someone who starts a designated use after the proposal but before the final rule takes effect must stop that activity when the rule becomes effective, then satisfy the applicable notification and review requirements before resuming. Final rule, sections I.B, II.B and III.A.