ERM recently attended the European Food Safety Authority’s (EFSA) training event on its forthcoming PECsoil (Predicted Environmental Concentrations in soil) guidance. When implemented, the guidance will fundamentally change the way PECsoil calculations are performed for plant protection products. A tiered approach uses the new model PERSAM as well as modified versions of the groundwater leaching models PEARL and PELMO. There are facilities to include the handling of pH-dependent substances, row crops and granular applications.

Tiers 1 and 2 use conservative default input parameters, producing higher PECsoil than current calculations. Tier 3 is more conservative than current calculations for short-lived substances (producing 1.3 to 2.1 x higher PECs) due to the inclusion of wash-off and changes to soil bulk density values. Tier 3 is potentially less conservative for persistent substances (producing 0.5 to 1.5 x higher PECs) due to the inclusion of leaching and the use of averaged as opposed to worst-case DT50 values.

New ecotoxicology guidance is also planned by EFSA, ultimately for use in conjunction with the new PECsoil approach. Currently EFSA does not foresee the new PECsoil guidance being used in regulatory submissions within the next year to 18 months. ERM’s experienced teams of environmental fate and ecotoxicology scientists will be happy to help you address potentially problematic soil exposure and risk assessments in advance of the new guidance’s implementation.

For advice on PECsoil assessment and further information on the registration of plant protection products, biocides or general chemicals, or any other regulatory issues, please contact ERM on +44 (0)1423 520245, enquiries-harrogate@erm.com.