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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:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
publication
Title:
Biodegradation and bioaccumulation data of existing chemicals based on the Chemical Substances Control Law (CSCL), Japan.
Author:
Ministry of International Trade and Industry (MITI)
Year:
1992
Bibliographic source:
Chemicals Inspection and Testing Institute (CITI) (ed.); Japan Chemical Industry Ecology - Toxicology and Information Center 1-27, 2-8.

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Chloroform
EC Number:
200-663-8
EC Name:
Chloroform
Cas Number:
67-66-3
Molecular formula:
CHCl3
IUPAC Name:
chloroform
Test material form:
liquid

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic, non-adapted
Details on inoculum:
Concentration of activated sludge (as the concentration of suspended solid): 30 mg/L
Duration of test (contact time):
14 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Details on study design:
The oxygen uptake by a stirred solution, or suspension, of the test substance in a mineral medium, inoculated with specially grown, unadapted micro-organisms, is measured automatically over a period of 28 days in a darkened, enclosed respirometer at 25 + 1°C. Evolved carbon dioxide is absorbed by soda lime. Biodegradation is expressed as the percentage oxygen uptake (corrected for blank uptake) of the theoretical uptake (ThOD). The percentage primary biodegradation is also calculated from supplemental specific chemical analysis made at the beginning and end of incubation, and optionally ultimate biodegradation by DOC analysis.

Results and discussion

% Degradation
Parameter:
% degradation (test mat. analysis)
Value:
0
Sampling time:
14 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
The test indicates that chloroform is not readily biodegradable in water under aerobic conditions.
Executive summary:

A test on the ready biodegradability of chloroform in water under aerobic conditions was carried out according to OECD Guideline No. 301 -C (MITI (I) test). The measurement of the biochemical oxygen demand indicated no oxygen consumption after 14 days showing that no biodegradation of chloroform occurred. The loss of chloroform as measured by gas chromatography after 14 days was 4.6 %. From these observations it can be concluded that chloroform is not readily biodegradable in water under aerobic conditions.