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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted according to OECD Guidelines, with no or minor deviations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Qualifier:
according to
Guideline:
EPA OPPTS 835.3110 (Ready Biodegradability)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Liquid
Details on test material:
Batch NX00002996
Purity 98.4%
Expiry Date 23.02.2012

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Duration of test (contact time):
90 d
Initial test substance concentration
Initial conc.:
30 mg/L
Based on:
test mat.

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Value:
>= 10
Sampling time:
8 d
Remarks on result:
other: Flask 5
Parameter:
% degradation (O2 consumption)
Value:
78
Sampling time:
28 d
Remarks on result:
other: Flask 5
Parameter:
% degradation (O2 consumption)
Value:
>= 10
Sampling time:
27 d
Remarks on result:
other: Flask 6
Parameter:
% degradation (O2 consumption)
Value:
20
Sampling time:
28 d
Remarks on result:
other: Flask 6
Details on results:
Flask 5 : %Degr 94% after 60 days and 101% after 90 days
Flask 6: %Degr 87% after 60 days and 104% after 90 days

Any other information on results incl. tables

Cumin Nitrile did not significantly inhibit the intrinsic respiration of the inoculum at the test concentration and was therefore considered to be non-toxic to the inoculum at the test concentration.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: Not Readily biodegradable but inherently and Ultimately Biodegradable.
Conclusions:
The two replicates showed different behaviour. In one test flask biodegradation started on day 8 and reached 78% after 28 days (i.e. passing the readily biodegradability criteria). However, in the other flask the onset of biodegradation was delayed, starting on day 27 and thus only achieving 20% after 28 days. Since the average biodegradation of the two replicates at 28 days was < 60%, Cumin Nitrile should be regarded as not readily biodegradable according to this test.
The test was prolonged and both replicates achieved high levels of degradation (i.e. 87% and 94% after 60 days; 101% and 104% after 90 days). Based on these results Cumin Nitrile should be regarded as inherently and ultimately biodegradable.