P
PBT Substance
Definition
A PBT (Persistent, Bioaccumulative, and Toxic) substance is a substance meeting the criteria set out in Annex XIII of REACH for all three properties simultaneously: persistence (degradation half-lives in water, sediment, or soil exceeding specified thresholds), bioaccumulation (bioconcentration factor (BCF) or bioaccumulation factor (BAF) exceeding specified thresholds), and toxicity (showing chronic toxicity effects in freshwater or marine organisms, or classified as CMR 1A/1B, or showing endocrine-disrupting effects). PBT substances qualify as SVHCs under REACH Article 57(d).
Source
REACH Regulation (EC) No 1907/2006, Article 57(d) and Annex XIII.
Practical Explanation (Compliance Context)
PBT assessment is required as part of the Chemical Safety Assessment (Annex I) for all registered substances. If a substance meets PBT criteria, a higher level of control is warranted: the substance qualifies for SVHC identification and may be added to the Candidate List. No safe use level (DNEL/PNEC) can be derived for PBT substances; instead, emission minimisation is required. Companies should proactively assess PBT properties for substances they manufacture or use.