Metabolites detected at >10% AR or at 2 successive times >5% AR were pencycuron-PB-amine (max. 45.0% AR on day 100), pencycuron-phenyl-cyclopentyl-urea (max 6.6% AR on day 91) and pencycuronketone (max 7.9% AR on day 77). Mineralisation of pencycuron (methylene-label) at 20°C represented 6.5-40.9% AR on day 84-91 (5 soils) and 4.7-46.3% AR on day 104-120 (12 soils). Mineralisation of pencycuron (phenyl-UL-label) at 20°C in four soils represented 19.3-27.4% AR on day 91 and 21.0-29.4% AR on day 104. Non-extractable residues never exceeded 70% AR: for pencycuron (methylene-label) (12 soils) maximum 11.2-24.0% AR after 100-120 days and for pencycuron (phenyl-UL-label) (4 soils) maximum 34.1-44.5% AR after 104 days. Aerobic metabolism of pencycuron proceeds due to hydrolysis and microbial processes. The ultimate breakdown products are CO2 and non-extractable residues.The proposed metabolic pathway with the identified degradation products is based on studies with pencycuron radiolabelled in the phenyl-ring or at the methylene position. The formation of the metabolite pencycuronpheyl- cyclopentyl-urea from pencycuron-ketone will lead to the loss of the chlorophenyl moiety. The formation of the metabolite pencycuron-descyclopentyl from pencycuron will lead to the loss of the cyclopentyl moiety. Due to the labelling positions of pencycuron in the submitted studies, information on the fate of these two moieties is not available. This information is required in order to assess whether any metabolites are formed for which an environmental risk assessment is required.