[14C]-Chlormequat-chloride degradation was studied in the four soils (Speyer 2.2, loamy sand; Itingen, silt loam; Collombey, loamy sand; Les Evouettes, silt loam). 
In three of the soils (Speyer 2.2, Collombey and Les Evouettes), the main route of dissipation of the parent compound was mineralisation (51.2-61.1% after 112 days of incubation). The amount of bound residue increased with time to 24.2-27.8% after 112 days. Volatile organic compounds accounted for ≤0.2% of the total AR at all time points. The Itingen soil differs from the other three soils with a slower rate of mineralisation (28.3% at 112 days) and a larger quantity of soil metabolites forming. Total amounts of unidentified soil metabolites accounted for more than 10% of the total AR at six consecutive time points, peaking at 43.7% at day 56. However, these metabolites were not identified further as the full route of degradation was performed for the Speyer 2.2 soil only. 
Extensive characterisation of extractable soil residues was carried out in a single soil, Speyer 2.2, in which only minor unidentified metabolites were found in the soil extracts (<10% of the total AR), with one unidentified metabolite which remained at the start position during the TLC analysis occurring at a maximum of 7.2% (>5% at two consecutive occasions). This unidentified metabolite did not co-chromatograph with either of the reference compounds tested (choline chloride and acetylcholine chloride) however it will require further consideration according to the EU Guidance document on assessing the relevance of metabolites in ground water (Ref. SANCO/221/2000-rev.10). 
The parent decay was fitted to first order kinetics following non-linear regression. The calculated DT50 values (at 20°C and normalised to field capacity moisture content) are 31.6, 19.8, 24.4, and 17.0 days for Speyer 2.2, Intingen; Collombey, Les Evouettes respectively (Geometric mean of 22.6 days). 
The Rapporteur noted that soils used to study the route and rate of degradation had relatively small clay contents (4.3-7.0%), lower than recommended by the SETAC guidelines (1995). In Section B.8.2.1 it was seen that the soil with the highest soil clay content demonstrated the highest adsorption of chlormequat-chloride. Therefore it is suggested by the Rapporteur that if soils with higher clay content had been used in the present study, adsorption could have been greater and therefore microbial degradation may have been reduced. When taking into account the relatively large margins of safety associated with the ground and surface water exposure assessments the Rapporteur considered that additional testing of further soils would not have resulted in a significantly different assessment. Therefore overall the Rapporteur accepted that the test soils selected provided an adequate estimation of degradation of chlormequat-chloride and no further information is required. .