Persistent (PBT Criterion)

The first PBT criterion. A substance is persistent when it resists environmental degradation and remains in soil, water, sediment, or air for extended periods. All five TSCA PBT chemicals are persistent.

TSCA § 6(h); EPA 2018 Assessments.

Persistence means any release contributes to cumulative environmental burden that does not naturally diminish. This drives regulatory focus on exposure reduction rather than environmental degradation management.

DecaBDE persists in sediments with half-lives exceeding years, which is why EPA prohibited its release to water in the 2024 revision.