The main degradation pathway of fenpropidin is biotic and occurs under oxidative conditions. Photochemical transformation is not an important route of degradation on soil. Several metabolites were identified but none of them represented >10% of the applied radioactivity in viable soils at standard laboratory conditions. CGA 289267 was identified as >10% of the applied radioactivity only in a soil having low biogical activity (sandy soil, Rümbeli, 1990) and in a test system incubated at 8ºC (sandy loam, Rümbeli, 1991). At 22ºC it was identified as max. 4.6% of the applied radioactivity. Metabolites CGA 289269 and possibly also CGA 289263 were identified in soil incubated at 22ºC but not quantified. However, since the sum of non-polar metabolites made up max. 5% of the applied radioactivity each one of them would have been present at less amounts. CGA 289269 (4-hydroxy derivative of fenpropidin) and CGA 289263 (N-oxide derivative of fenpropidin) are products of oxidation of the piperidine ring. CGA 289268 and NOA 406117 are formed by hydroxylation of the tertiary butyl side chain or the methyl side chain, respectively, and further oxidised to CGA 289267 and NOA 406116. Cleavage of the N-methylpropyl bridge and loss of the piperidine ring with subsequent oxidation to CGA 289274 was also observed. Document M-II presented a scheme of the proposed metabolic pathway of fenpropidin in soil. The RMS agrees to that scheme but has chosen to show a scheme (Figure 8.1.5) presented in the field dissipation study by Krauss (2000), performed on radiolabelled test substance, because in that all the above mentioned metabolites were identified and quantified. However, they were all minor.