Of the metabolites described in the degradation scheme, all except JK543 are considered as major metabolites in one or more test systems. Four different pathways were used for the kinetic analysis of the aerobic soil degradation studies, and one additional pathway for anaerobic degradation. The conceptual models used are described in Appendix IIA. Comparing the different conceptual models for degradation pathways with the degradation scheme given above, the justification behind the selected models is not very clear. For instance, parameters for IN-A8342 was sometimes optimised as if it was formed only directly from azimsulfuron, but if the metabolite IN-A8342 is formed both directly from the parent compound and via either of the two primary metabolites IN-JJ999 and IN- KQ962 (as in the proposed aerobic degradation scheme above) these latter routes should not be ignored in the optimisation. Similarly, the conceptual model for parameterisation of IN-H9235 under anaerobic conditions assumed that IN-J290 was the sole precursor, while from the proposed degradation scheme this metabolite was also formed via IN-JJ999.