Registration Dossier

Environmental fate & pathways

Biodegradation in soil

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Half-lives under aerobic conditions: < 1 h and 1.7 days
Half-life under anaerobic conditions: 14.12 days

Key value for chemical safety assessment

Additional information

The biodegradation of zinc bis dimethyldithiocarbamate (CAS No. 137-30-4) in soil was investigated in several studies under both aerobic and anaerobic conditions. The aerobic key study by Mamouni (2001) was conducted according to US EPA Guideline, Subdivision N162-1, Aerobic Soil Metabolism Studies (1986), under GLP conditions.14C-labeled Ziram was incubated in three different soil types (loamy sand, sandy loam and silt loam) at 20°C (with an additional 10°C loamy sand incubation group) for 28 days. The resulting half-life was determined to be below 1 hour for all three soil types at both tested temperatures. Several metabolites originated from the degradation of the parent compound. The main products from this degradation process were14CO2 and Thiram (substance degraded within 3 days since first detected). An additional study (Heasook, 1996) investigated the biodegradation of14C-labeled Ziram in soil under aerobic conditions. This test was conducted also according to US EPA Guideline, Subdivision N162-1 under GLP conditions and it was extended to 60 days. A half-life of 1.7 days was reported, with 1,1-dimethylurea and14CO2 as major metabolites.

Under anaerobic conditions (Reynolds and Smalley, 1997), the measured half-life of14C-labeled Ziram was 14.12 days. The metabolite profile of this substance did not differ between aerobic and anaerobic conditions, being14CO2 a relevant product of the degradation process.

 

Additional studies are available regarding biodegradation of zinc bis dimethyldithiocarbamate in soil but due to methodological deficiencies were disregarded for further assessment (Cranor, 1987a, 1987b).