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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:
1996
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)
Deviations:
no
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
1-bromohexane
EC Number:
203-850-2
EC Name:
1-bromohexane
Cas Number:
111-25-1
Molecular formula:
C6H13Br
IUPAC Name:
1-bromohexane
Test material form:
not specified
Details on test material:
No details

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
not specified
Duration of test (contact time):
29 d
Initial test substance concentrationopen allclose all
Initial conc.:
4.03 mg/L
Based on:
test mat.
Initial conc.:
2 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
Four series of tests:
- 1: Medium + inoculum
- 2: Medium + inoculum + test substance
- 3: Medium + inoculum + test substance + reference substance
- 4: Medium + inoculum + reference substance
Each series was done with two flasks execpted the one with test substance which was done with 3 flasks.
Analyses done at 0, 7, 15, 22 and 29 days
Reference substance
Reference substance:
benzoic acid, sodium salt
Remarks:
At 2 mg/L in serie 3 and 4 mg/L in serie 4

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Value:
-1.7
Sampling time:
7 d
Parameter:
% degradation (O2 consumption)
Value:
-0.5
Sampling time:
15 d
Parameter:
% degradation (O2 consumption)
Value:
1.1
Sampling time:
22 d
Parameter:
% degradation (O2 consumption)
Value:
7
Sampling time:
29 d

BOD5 / COD results

Results with reference substance:
%degradation of reference substance is : 80.5% after 7 days, 83.2% after 15 days, 85.9% after 22 days and 88.8% after 29 days

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
%degradation of reference substance > 60% after 14 days; oxygen depletion in blank test < 1.5 mg/L after 28 days; %degradation of reference substance > 25% after 14 days in inhibition test; residual oxygen concentration on test flasks always > 0.5 mg/L
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
With a biodegradability of 7.0% after 28 days, 1-Bromohexane is determined as no biodegradable
Executive summary:

The biodegradability study of 1-Bromohexane gives a maximum of 7.0% after 28 days.

The validity criteria of the method were respected.

According to these criteria the test item cannot be considered as ready biodegradable.