The T-value in the score for hazard refers to acute toxicity. Underlying data for P, B, T and risk are from Fass Nix (permethrin) (downloaded 2013-09-03). No new environmental information for permethrin is published on Fass.se (2018-09-06). It is voluntary for manufacturers to provide information about environmental impact on Fass.se.
Fass environmental information for Nix (permethrin) (downloaded 2013-09-03).
Persistence: The half-life of soil degradation is 5-55 days. It is indicated that permethrin is slowly degraded in the environment.
Bioaccumulation: Permethrin has a high potential for bioaccumulation (BCF 400-20 000 [fish]). The substance has high log KOW (6.5 i 25°C) and the properties are confirmed in studies on e.g. fish.
Acute toxicity: There is data for 3 trophic levels, lowest for crustacean (D. magna) 0.0001 mg/L.
PEC/PNEC is based on sales data in Sweden "in the last year" (unclear what year it means). PEC/PNEC = 1.7 which gives the risk moderate.
Author: Department of Strategic Careers, Stockholm County Council.