The notifier states that guazatine will dissipate from the seed surface to soil by various physical chemical processes, e.g. desorption, solubilsation (of ions or ion pairs), in combination with capillary movement and partition processes. Biological dissipation and transport may also occur e.g. through root formation, as well as microbial transformation, degradation, some irreversible binding and eventual mineralisation to CO2. Aerobic degradation of guazatine was investigated in the laboratory (Class, T. 2004) by applying the 3 major components of guazatine, [14C]-labelled GN, GG and GGG in mixture to wheat seeds planted in soil and incubated in the dark for ca. 120 days at 10°C (1 soil) or 20°C (4 soils). The seed, core soil (soil attached to roots) and bulk soil (remaining soil) were extracted and analysed at about 8 intervals. The majority of applied radioactivity was detected either as the starting material, GN, GG and GGG or mineralised to 14CO2. Recovery was generally acceptable (86-116% AR) with 2 exceptions (74-76% AR) attributed to loss as CO2. GG was the dominant component, with (based on changes in radioactive ratios of the 3 components taken from chromatograms) GGG appearing to adhere the seed and show slower migration to soil than GG or GN. GN appeared to dissipate faster from the seed to soil than GG or GGG. Other metabolites characterised were only present at very low levels e.g. U2m, GNG and GGn were <1% AR at any sampling inerval. Metabolites U9m and U10m were up to <3 and <5% AR, respectively, but were subsequently separated into several smaller peaks). Unassigned radioactivity was <6% AR at any sampling interval. After ca. 120 days incubation, mineralisation to 14CO2 ranged from 44 to 65% AR at both 20°C and 10°C and unextracted residues were 5-9% AR and 3% AR at 20°C and 10°C, respectively. The following metabolic pathway is that proposed by the notifier for guazatine in soil: It is claimed that under aerobic conditions, guazatine is metabolised by deguanidation of the -C(NH2)=NH moieties, so that GG is converted to NN via GN. Deguanidation of GGG is also presumed to result in formation of intermediates and possibly NNN. The intermediate products formed by deguanidation, also present in the parent polyoligomeric mixture, change in relative ratio during “degradation”, so that the guanidated components decrase while the deguanidated components increase. Further minor metabolites may also result from enzymatic oxidation, hydroxylation, and deamination at the primary (in GN) or secondary (in GN, GG and GGG) amino moieties or at the corresponding [14C]-radio-labelled alpha C-atoms. It is proposed that further oxidation and C-C bond cleavage at these sites gives rise to 14CO2. GN was the component most readily mineralised to CO2, with slightly less CO2 formed from GG and much less mineralisation from GGG. Minor metabolites were tentatively assigned in radiochromatograms based on retention times relative to test items.