It is noted that isopyrazam exists as syn and anti isomers. Analysis to ascertain the syn:anti isomer ratio during the studies was conducted, and there was no evidence to suggest that the ratio of isomers changed significantly with time in aerobic soil systems. Unextracted residues were relatively low in three out of the four soils tested with the phenyl-labelled a.s., the range being 2.6-5.2% AR at 120 days on these three soils; volatile radioactivity (assumed to be CO2) was also low at <1% AR at the same time. On the fourth soil (Gartenacker) with the phenyl label, unextracted residues were 9.8-12.8% AR at 120-123 DAT, this increasing to 23.1-29.6% AR at 361 - 369 DAT; CO2 was slightly higher in this particular soil at 0.9-1.6% AR at 120 DAT and 1.5-2.3% at 369 DAT. It was also noted that decline of isopyrazam was significantly greater on this soil with the greatest formation of unextractable residues, suggesting that degradation of the a.s. leads to greater formation of unextracted residues, rather than ultimate degradation to CO2. In the single soil (Gartenacker) tested with the pyrazole labelled a.s., unextracted residues as 120 DAT were 25.7% AR with CO2 at 3.2% AR; at 360 DAT, unextracted residues had rison to 58.3% AR and CO2 to 22.7% AR. It was noted that the decline of isopyrazam was even greater in this particular study than in the equivalent study using the phenyl-labelled a.s. with the same soil (46.7% AR remaining with phenyl label at 120 DAT compared to 15.3% AR at the same time with the pyrazole label). In the study on the pyrazole-labelled a.s., two major metabolites were identified, CSCD 459488 at max. 22.3% AR at 45 DAT, and CSCD 465008 at max 11.5% AR at 150 DAT. Formation of CSCD 465008 involves cleavage of the molecule between the two ring systems such that CSCD 465008 only contains the pyrazole ring. This study also showed up to 33 individual but minor components, the maximum level of which was 4.75% AR. The Applicant clarified that at the end of the study, whilst total unidentified radioactivity constituted 18.9% AR, individual components were maximum 2% AR, i.e. the unidentified metabolite at 4.75% AR had declined in concentration. Thus the RMS considers no further consideration of unidentified radioactivity is required. Thus the route of degradation of isopyrazam would appear to be degradation at variable rate through metabolites CSCD 460260 (i.e. mixture of CSCD 459488 and CSCD 459489) and CSCD 465008 to a large number of minor unidentified products to form predominantly unextracted material. It would appear that ultimate mineralisation from isopyrazam is relatively slow. However, the relatively higher mineralisation in studies where CSCD 465008 was applied (10-66% AR at study end) give some reassurance that mineralisation will occur.