Non-Isolated Intermediate (PFAS)

A non-isolated intermediate is a PFAS substance that is produced and consumed within a continuous chemical manufacturing process without being deliberately removed from the reaction vessel, accumulating in storage, or being transferred between facilities. The November 2025 proposed revision to TSCA 8(a)(7) would exempt non-isolated intermediates from reporting, recognizing that these transient substances may never exist outside the reactor and are often uncharacterizable.

EPA November 2025 Proposed Rule (90 FR 50923); 40 CFR Part 705; TSCA §3.

This proposed exemption is particularly relevant for chemical manufacturers that produce PFAS as part of multi-step synthesis processes. If a PFAS intermediate is formed and immediately consumed in the next reaction step without ever being isolated, it would not require separate reporting. Companies should document their manufacturing process flows to demonstrate that intermediates qualify as non-isolated.

A fluorochemical manufacturer produces a PFAS intermediate during fluorotelomer synthesis that is immediately consumed in the next reaction step within the same reactor. Under the proposed non-isolated intermediate exemption, this transient substance would not need to be separately reported under TSCA 8(a)(7).