Biota EQS

For substances that bioaccumulate in living organisms (fish, crustaceans, molluscs), compliance cannot be reliably assessed from water concentrations alone. A biota EQS is expressed in μg/kg wet weight (ww) or dry weight (dw) and must be measured in the relevant biological tissue. For PFAS (substance No.65), the biota EQS (0.077 μg/kg ww in fish) is the primary compliance criterion per Annex VI footnote 27 — water measurements are not equivalently protective.