The fate and behaviour of IKF-309 in soil has been investigated laboratory studies using 14C-labelled IKF-309 (labelled in the pyridyl and phenyl rings) and in field trials. The route and rate of degradation of IKF-309 was investigated in the laboratory in an aerobic sandy loam soil at a moisture content equivalent pF2 and temperature of 20°C. A further study was performed on 3 soils (1 sandy loam and 2 clay loam soils) at pF2 and 20°C, with an additional study on a clay loam at 10°C. The pH of the four soils used ranged from 4.8 to 7.4 when measured water which is an acceptable range as the rate of degradation is not expected to be pH dependent (on the basis of no degradation in the hydrolysis study and no pH dependence in the 4 soils tested). IKF-309 degraded in aerobic sandy loam soil at 20�C via 3HDPM (max. formed = 3.6% AR), 4HDPM (max. formed = 3.2% AR) and 2MDPM (max. formed = 2.1% AR) to form carbon dioxide and bound residues. A further 5 minor components were also present but no metabolites were triggered for inclusion in the exposure assessment. Organic volatiles were less than 0.3% AR.