1H-1,2,4-Triazole-1-carboxamide, 4-amino-N-(1,1-dimethylethyl)-4,5-dihydro-3-(1-methylethyl)-5-oxo-

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

Guideline:

EPA OPPTS 835.4300 (Aerobic Aquatic Metabolism)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-N-tert-butyl-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide

EC Number:

603-373-3

Cas Number:

129909-90-6

Molecular formula:

C10H19N5O2

IUPAC Name:

4-amino-N-tert-butyl-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide

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.

% Degradation

% Degradation 1

% Degr.:

103

Parameter:

test mat. analysis

Sampling time:

0 d

Remarks on result:

other: Sid White Pond

% Degradation 2

% Degr.:

82.6

Parameter:

test mat. analysis

Sampling time:

100 d

Remarks on result:

other: Sid White Pond

% Degradation 3

% Degr.:

97.2

Parameter:

test mat. analysis

Sampling time:

0 d

Remarks on result:

other: Econfina Marine

% Degradation 4

% 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)

Half-life of parent compound / 50% disappearance time (DT50) 1

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

Half-life of parent compound / 50% disappearance time (DT50) 2

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 products

Identity of transformation products 1

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

desamino amicarbazone

Identifier:

common name

Identity:

desamino amicarbazone

Identity of transformation products 2

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

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.