In the aerobic degradation study of Smith-Drake.J.K., et al., 2007 conducted at 20 oC up to two major metabolite peaks (concentrations > 10 % AR) were identified in the full mass balance studies conducted with XDE-175-J as N-demethyl-J and Ndemethyl- N-nitroso-J. An additional non-transient minor metabolite which occurred at a maximum concentration of 8.9 % AR was also identified, as N-succinyl-J, as it occurred at concentrations greater than 5 % AR on consecutive sampling occasions. For studies conducted with XDE-175-L three major metabolites were identified in aerobic soil degradation studies as N-demethyl-L, N-demethyl-N-nitroso-L and Nsuccinyl- L. All three occurred at concentrations > 10 % AR. In the study of Yoder, et al. 2005, because it was conducted to US guidelines only metabolites which occurred at concentrations > 10 % AR were identified. Consequently only the N-demethyl-J and N-demethyl-L metabolites were characterised in this study. However, the number of metabolites which occurred in any sample at concentrations < 2 % AR, between 2 and 5 % AR and between 5 and 10 % AR was quoted. Up to four unidentified metabolites were observed at concentrations > 5 % AR at any one time-point, and on several occasions unidentified metabolites were observed at consecutive time-points. Since retention times are not quoted for any of these unidentified metabolites, from the information supplied in the report it is not possible to say whether any of these additional metabolites should have been characterised according to EU guidelines. The applicant states that the samples were discarded upon study finalisation and that therefore no further analysis is possible. The RMS considers that this is unfortunate, but that a fully acceptable route of degradation study has been supplied by the applicant. The study of Yoder et al. 2005 therefore has to be considered as supportive in this regard. However contrary to the Applicants opinion the RMS considers that otherwise the study was conducted in an appropriate manner and that the remaining end-points from it are appropriate for use in subsequent risk assessments. Unextracted radioactivity and 14CO2 were characterised in both studies. Mineralisation increased during the course of the experiments performed with all 8 soils for XDE- 175-J. The maximum concentration of 14CO2 observed at 125 – 127 d was 19.1 % AR for the Slagle loam soil, however this result was much higher than for the remaining seven soils where the range was 0.4 – 2.3 % AR at the same time-point. In the four soils where the study was conducted for longer, concentrations continued to increase until study termination reaching a maximum of 35.2 % AR in the Slagle Loam and 7.7 – 7.8 otherwise (276 – 366 days). A similar effect was observed for the experiments conducted with XDE-175-L, where the maximum concentrations at 123 – 127d were 23.7 % AR in the Slagle Loam but 1.2 – 8.0 % AR otherwise. Maximum observed unextracted radioactivity concentrations for either XDE-175-J or XDE-175-L were 4.6 – 35.6 % AR at 123 – 127 d.