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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: acceptable, well documented study report which meets basic scientific principles; Adopted according to OECD SIDS. The original source is available and has been reviewed

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1979
Report date:
2002
Reference Type:
review article or handbook
Title:
1-chloro-4-nitrobenzene
Author:
OECD SIDS
Year:
2002
Bibliographic source:
SIDS Initial Assessment Report for SIAM 15, UNEP Publications

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
1-chloro-4-nitrobenzene
EC Number:
202-809-6
EC Name:
1-chloro-4-nitrobenzene
Cas Number:
100-00-5
Molecular formula:
C6H4ClNO2
IUPAC Name:
1-chloro-4-nitrobenzene
Details on test material:
- Name of test material (as cited in study report): p-nitrochlorobenzene
-Test substance: other TS: purity 98.8 %

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
other: non adapted
Details on inoculum:
-Effluent of a 3 L labour sewage treatment plant in accordance with OECD, working with full nutrient medium.
-Type: mixed population of aquatic micro-organisms
Duration of test (contact time):
20 d
Initial test substance concentrationopen allclose all
Initial conc.:
2.4 mg/L
Based on:
test mat.
Initial conc.:
8 mg/L
Based on:
test mat.
Initial conc.:
24 mg/L
Based on:
test mat.
Initial conc.:
80 mg/L
Based on:
test mat.
Details on study design:
- Pre-treatment of the test substance: The concentration of the test substance in the stock solution was 1 g/L. The substance was not properly soluble in this concentration and was therefore emulsified. It was used Emulsifier W (CAS number 68130-72-3) which shows not BOD in this test.
- Concentration of inoculum: 1000 to 1000000 bacteria per litre (little bacteria density)
- Incubation time was 0, 5, 10, 20 days at 20 °C ± 1 °C
- Incubation in the dark
- 1-Chloro-4-nitrobenzene was the only source of organic carbon.

The following type of flasks were used:
- Test suspension 1 (4 bottles) A measured volume of mineral medium containing a known concentration of the test substance (as the nominal sole
source of organic carbon) and inoculum.
- Procedure control: In order to check the procedure, the reference chemical Phenol is tested parallel to the normal test runs.
- Inoculum blank: A measured volume of mineral medium containing only inoculum.
Reference substance
Reference substance:
other: phenol

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Value:
0
Sampling time:
5 d
Parameter:
% degradation (O2 consumption)
Value:
0
Sampling time:
10 d
Parameter:
% degradation (O2 consumption)
Value:
0
Sampling time:
20 d

Any other information on results incl. tables

Year: 1979 ("Year of study completion".)

Applicant's summary and conclusion

Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
p-Nitrochlorobenzene showed with non adapted inoculum:
used concentrations: 2.4 mg/L; 8.0 mg/L, 24 mg/L, 80 mg/L
0 % degradation after 5 days.
0 % degradation after 10 days.
0 % degradation after 20 days.
Therefore p-nitrochlorobenzene has to be classified as not readily biodegradable.
Executive summary:

Mendel B; Bayer AG, 1979 (report: 2002)

The ready biodegradability was studied with a method corresponding to the OECD 301 D. The test concentrations were 2.4 mg/L, 8.0 mg/L, 24 mg/L and 80 mg/L. and the innoculum concentration was 1000 -1000000 bacteria/L. In the aerobic study, the degradation of 1-chloro-4-nitrobenzene with non adapted inoculum was 0 % degradation after 5 days, 0 % degradation after 10 days, 0% degradation after 20 days. Therefore 1-chloro-4-nitrobenzene (p-nitrochlorobenzene) has to be classified as - not readily biodegradable.

Comments: Toxic effects were seen in concentrations of 80 mg/L after 10 days (Degradation of the test substance 1-chloro-4-nitrobenzene with adaptation; the same Study 7900802-815).