From: Proposal for a harmonised PBT identification across different regulatory frameworks
Persistence | ||
---|---|---|
Definitive assessment | Screening assessment | |
Criteria | Half-life | Ready biodegradability |
Water: | Enhanced ready biodegradability | |
> 60 days in marine (>60 days) | ||
> 40 days in fresh- or estuarine (>60 days) | ||
Sediment: | ||
> 180 days in marine (>180 days) | ||
> 120 days in fresh- or estuarine (>180 days) | ||
Soil: | ||
> 120 days (>180 days) | ||
Proposal | Considering DegT50 and not DissT50 | Other information to consider |
Normalising DegT50 to 12°C | Abiotic degradation | |
Inclusion of field studies if DegT50 can be derived | Monitoring data | |
Selecting DegT50 from multiple studies: | QSAR | |
For ≤4 values: worst case | Read-across from structurally related substances | |
For ≥5 values: geometric mean, or WoE | ||
Water and sediment systems: comparing DegT50 to trigger | ||
Values of water and sediment; need clear criteria | ||
Other information to consider | ||
Formation of NER or mineralisation rate |