Chlorinated Fatty Acid Methyl Ester

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

1992 version

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

methyl tetradecanoate, chloro

Molecular formula:

C13H26Cl4COOCH3 and C13H25Cl5COOCH3 (primary isomers based on product weight of 35-40% Cl by weight)

IUPAC Name:

methyl tetradecanoate, chloro

Constituent 2

Reference substance name:

Methyl octadecanoate, chloro

Molecular formula:

C17H30Cl4COOCH3, C17H29Cl5COOCH3 , and C17H28Cl6COOCH3 (primary isomers based on 35-40% Cl by weight)

IUPAC Name:

Methyl octadecanoate, chloro

Constituent 3

Reference substance name:

Methyl hexadecanoate, chloro

Molecular formula:

C15H28Cl4COOCH3 and C15H27Cl5COOCH3 (primary isomers based on 35-40% Cl by weight)

IUPAC Name:

Methyl hexadecanoate, chloro

Test material form:

liquid

Details on test material:

This is a UVCB substance developed from the chlorination of fatty acid methyl esters.

Specific details on test material used for the study:

Batch A070806

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Aerobic activated sludge from a local wastewater treatment plant, treating predominantly domestic wastewater. The final concentration of the sludge in the test flasks was 30 mg dry material per liter.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

30 mg/L

Based on:

test mat.

Remarks:

dry material weight

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Apparatus: The test flasks (500-ml Erlenmeyer flasks, labeled with the necessary information to ensure unmistakable identification) were incubated (in darkness) under continuous stirring in a SAPROMAT D12 (Veith GmbH, Heidenheim, Germany). Oxygen consumption was recorded manually by taking a reading at least on each working day.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

Not conducted.

Test performance:

Acceptable based on positive control and similarity of replicates.

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

91

Sampling time:

28 d

Remarks on result:

other:

Remarks:

Mean of two replicates.

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

86

Sampling time:

28 d

Remarks on result:

other: Replicate #1

% Degradation 3

Parameter:

% degradation (O2 consumption)

Value:

95

Sampling time:

28 d

Remarks on result:

other: Replicate #2

Details on results:

chemical oxygen demand (COD) of 1.04 mg oxygen (O2) per mg test item.

BOD5 / COD results

Results with reference substance:

The percent biodegradation of the reference item sodium benzoate was calculated based on the theoretical oxygen demand of 1.67 mg O2/mg (ThOD). In the procedure controls, the reference item was degraded by an average of 92% by Exposure Day 14, thus confirming suitability of the activated sludge.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

The mean biodegradation was 91% after 28 days (86% and 95% in the two replicates). While the 10-day window for 60% biodegradation was not achieved, as this is a UVCB substance, this metric is not considered as relevant as the overall biodegradation. Therefore, based on the overall biodegradation in 28 days, C16 and C18 chlorinated methyl esters are considered to be readily biodegradable.

Executive summary:

The mean biodegradation was 91% after 28 days (86% and 95% in the two replicates).  While the 10-day window for 60% biodegradation was not achieved, as this is a UVCB substance, this metric is not considered as relevant as the overall biodegradation. Therefore, based on the overall biodegradation in 28 days, C16 and C18 chlorinated methyl esters are considered to be readily biodegradable.