The route of degradation of dodine in the laboratory, under aerobic conditions was assessed in a sandy loam soil at 25 ºC (Cooper. et al., 1996), and in a sandy silt loam, clay loam and sand soil at 20 ºC (Lowden P et al, 1997). The results of the experiment conducted with the guanidine labelled dodine show that the a.s. is quickly metabolised in soil and its degradation ultimately resulted in a formation of CO2 without formation of any major metabolite or persistent unextractable residues. Degradation of dodine occurred by fragmentation of the molecule in three parts: dodecane, guanidine and acetic acid. The guanidine and the dodecane chain should be rapidly used by soil microflora. Minor metabolites were detected, but not identified, one of the metabolite should be guanidine that ultimately degrades to CO2. The minor metabolites should be molecules in which the chain length had been reduced (by β-oxidation) or to which additions have been made (e.g. hydroxidation). Both dodine+OH and dodine+CH2 were identified (by mass spectrometry) as minor synthetic impurities in the test material. The results of the experiment conducted with chain labelled dodine show that the dodecyl moiety of the molecule was also ultimately degraded to carbon dioxide. Incorporation of the partially degraded chain resulted in disappearance of parent material at a similar rate to that seen in the guanidine labelled experiments but with a slightly delayed evolution of radiolabelled carbon dioxide. Intermediate metabolites were produced in very small quantities and were themselves degraded without a build up of residues remaining associated with the soil.