Registration Dossier

Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:
biodegradation in water: sediment simulation testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OPPTS 835.4300 (Aerobic Aquatic Metabolism)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
3.19 MBq/mg
Radiolabelling:
yes

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
natural water / sediment
Details on source and properties of surface water:
Sid White pond (pH 7.4) and Econfina marine (pH 8.1) from Florida
Details on source and properties of sediment:
Sid White pond (clay, 0.6% OM, pH 6.2) and Econfina marine (sand, 4.7% OM, pH 7.6) from Florida
Duration of test (contact time):
100 d
Initial test substance concentration
Initial conc.:
0.5 other: micrograms/g
Based on:
test mat.
Details on study design:
Duplicate samples collected at 0, 7, 14, 30, 62 and 100 days

Results and discussion

Test performance:
Aerobic microbial activity was tested and showed that the sediment was viable throughout the study. The systems remained aerobic throughout the study.
% Degradationopen allclose all
% Degr.:
103
Parameter:
test mat. analysis
Sampling time:
0 d
Remarks on result:
other: Sid White Pond
% Degr.:
82.6
Parameter:
test mat. analysis
Sampling time:
100 d
Remarks on result:
other: Sid White Pond
% Degr.:
97.2
Parameter:
test mat. analysis
Sampling time:
0 d
Remarks on result:
other: Econfina Marine
% Degr.:
64.2
Parameter:
test mat. analysis
Sampling time:
100 d
Remarks on result:
other: Econfina marine
Half-life of parent compound / 50% disappearance time (DT50)open allclose all
Compartment:
entire system
DT50:
385 d
St. dev.:
0.763
Type:
(pseudo-)first order (= half-life)
Remarks on result:
other: DT90 1279.2 days Pond
Compartment:
entire system
DT50:
182.4 d
St. dev.:
0.959
Type:
(pseudo-)first order (= half-life)
Remarks on result:
other: DT90 605.9 days Marine
Transformation products:
yes
Identity of transformation productsopen allclose all
No.:
#1
Reference
Reference substance name:
Unnamed
IUPAC name:
desamino amicarbazone
Identifier:
common name
Identity:
desamino amicarbazone
No.:
#2
Reference
Reference substance name:
Unnamed
IUPAC name:
Decarboxamide amicarbazone
Identifier:
common name
Identity:
Decarboxamide amicarbazone
Details on transformation products:
#1 max 4.0% pond, 16.7% marine; #2 max 1.3% pond, 8.0% marine
Evaporation of parent compound:
not measured
Volatile metabolites:
yes
Residues:
yes
Details on results:
Bound residues max. 7% at 100 days; CO2 max 0.3% AR at 100 days.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Total system DT50s of 385 and 182.4 days with mass balances in the range of 100.7 +/- 3.5% and 99.2 +/- 2.3% for the pond and marine systems respectively.
Executive summary:

The aerobic aquatic degradation of amicarazone was determined in two water/sediment systems, a pond and a marine system. Amicarbaxone degraded slowly with DT50's of 385.0 and 182.4 days for the pond and marine systems respectively. Mass balances were within the 90 -110% range (95.1 to 108.5% for all samples). The main metabolites were desamino amicarbazone and decarboxamide amicarbazone.