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Environmental fate & pathways

Biodegradation in water: screening tests

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Endpoint:
biodegradation in water: screening test, other
Remarks:
BOD5/COD evaluation
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
March 3, 1976
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Principles of method if other than guideline:
The evaluation of BOD5 anc COD were conducted according to Internal standard methods: Internal method Nr.15 (BOD5); Internal method Nr.16 (COD)
GLP compliance:
no
Remarks:
Study conducted before 1981
Oxygen conditions:
aerobic
Inoculum or test system:
not specified
Duration of test (contact time):
ca. 5 d
Initial conc.:
ca. 5 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- pH: 3.4 (1 g/l )
Remarks on result:
not determinable
Parameter:
BOD5
Value:
ca. 200 mg O2/g test mat.
Parameter:
COD
Value:
ca. 1 079 mg O2/g test mat.
Parameter:
BOD5*100/COD
Value:
ca. 19
Interpretation of results:
not readily biodegradable
Conclusions:
BOD5= 200 mg O2/g
COD= 1079 mg O2/g
BOD5/COD= 0.19
Executive summary:

Method:

Internal method Nr. 16 and Nr.15

Results:

BOD5= 200 mg O2/g

COD= 1079 mg O2/g

BOD5/COD= 0.19

Based on the ECHA Guidance R7.b, if BOD5:COD ratio is 0.5 or higher, the substance is regarded as being readily biodegradable. The BOD5 and COD Ratio of the substance is lower than 0.5 therfore the test item can be considered as not readily biodegradable.

Endpoint:
biodegradation in water: screening test, other
Remarks:
TOC Evaluation
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
February 28, 1977
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
abstract
Principles of method if other than guideline:
The test was conducted according to a not specified Internal Standard Method
GLP compliance:
no
Remarks:
Study conducted before 1981
Oxygen conditions:
not specified
Inoculum or test system:
other: Huntingdon and Godmanchester Sewarage Treatment works, Cambridgeshire
Details on inoculum:
- Source of inoculum/activated sludge: Huntingdon and Godmanchester Sewarage Treatment works, Cambridgeshire
Duration of test (contact time):
ca. 14 d
Initial conc.:
ca. 400 mg/L
Based on:
other: TOC
Parameter:
% degradation (TOC removal)
Value:
ca. 60
Sampling time:
3 h
Parameter:
% degradation (TOC removal)
Value:
ca. 53
Sampling time:
14 d
Remarks on result:
other: Range of elimination: 41 - 64 %
Remarks:
Period of averrage: 1 - 4 d
Interpretation of results:
other: results not clear
Conclusions:
Average TOC removal (14 days) = 53 %
Absorption (3 h) = 60 %
Executive summary:

The TOC value was calculated with an internal method. Only a short abstract is available for this test. The average TOC removal calculated after 14 days was 53 % and the absorption after 3 h was 60 %. The results obtained from this test is not easy to be interpretated.

Description of key information

BOD5/COD= 0.19
TOC removal (14 days) = 53 %

Key value for chemical safety assessment

Additional information

Different available tests may be valuable that gives information on biodegradability.

BOD5/COD ratio

Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) are the most commonly used parameters for the characterization of the biodegradability capacity.

COD results are typically higher than BOD5 values, and the ratio between vary depending on the characteristics of the substrate. This ratio has been commonly used as an indicator for biodegradation capacity, the "Biodegradability index" (B.I.).

As indicated in ECHA Guidance requirement R.7B, the BOD5 test is a traditional biodegradation test that is now replaced by the ready biodegradability tests. Therefore, this test should not be performed today for assessment of the ready biodegradability of substances. Older test data may, however, be used when no other degradability data are available: if BOD5:COD ratio is 0.5 or higher, the substance is regarded as being readily biodegradable

Studies on BOD5 and COD are available for this substance, therefore they have been used to evaluate the potential of readily biodegradation.

COD was measured according to Method A-16. Details of the method have been not reported. The COD measured was 1079 mg/g O2.

BOD5 was measured according to Method A-15. Details of the method have been not reported. The BOD5 measured was 200 mg/g O2, at concentration of 100 mg/l.

The ratio BOD5/COD is 0.19 therefore the substance is considered as non readily biodegradable.

TOC

The TOC value was calculated with an internal method. Only a short abstract is available for this test.

The average TOC removal calculated after 14 days was 53 % and the absorption after 3 h was 60 %. The results obtained from this test is not easy to be interpretated.

Based on the available information the susbstance is considered in a protective manner as non readily biodegradable.