Alkanes, C10-13, chloro

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published study considered acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Bacterial cometabolic degradation of chlorinated paraffins

Author:

Omori T, Kimura T and Kodama T

Year:

1987

Bibliographic source:

Applied Microbiol. Biotechnol. 25: 553-557.

Reference 2

Reference Type:

secondary source

Title:

Unnamed

Year:

2000

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The degradation of Toyoparax 265 (a C12 chlorinated paraffin; 63% chlorination) was assessed by monitoring the release of chloride ion using a mixed bacterial culture isolated from soil.

GLP compliance:

not specified

Test type:

laboratory

Test material

Test material information

Constituent 1

Reference substance name:

Alkanes, C10-13, chloro

EC Number:

287-476-5

EC Name:

Alkanes, C10-13, chloro

Cas Number:

85535-84-8

IUPAC Name:

Alkanes, C10-C13, Chloro

Details on test material:

- Name of test material (as cited in study report): Toyoparax 265
- Substance type: technical product
- Physical state: no data
- Analytical purity: no data
- Composition of test material, percentage of components: C12 chlorinated paraffin (63% chlorinated; C12H18Cl8 )

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
no data

Radiolabelling:

no

Study design

Oxygen conditions:

aerobic

Soil classification:

not specified

Details on soil characteristics:

no data

Duration of test (contact time)

Soil No.:

#1

Duration:

ca. 48 h

Initial test substance concentration

Soil No.:

#1

Initial conc.:

ca. 180 other: mg chlorine/1.2 L solution

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: chloride ion release

Experimental conditions

Soil No.:

#1

Temp.:

30oC

Details on experimental conditions:

Bacterial strains were isolated from soil using an enrichment culture containing n-hexadecane as the sole carbon source. The cometabolic biodegradation experiments were carried out with Toyoparax 265 (designated soil sample No. #1), with a concentration equivalent to 180 mg Cl/l.2 L solution) using a mixed bacterial inoculum (containing strains HK-3, HK-6, HK-8 and HK-10) incubated at 30oC for 48 hours.

Results and discussion

% Degradation

Soil No.:

#1

% Degr.:

21

Parameter:

other: chloride release

Sampling time:

36 h

Transformation products:

not specified

Details on transformation products:

no data

Details on results:

Around 21% dechlorination of the test material was seen, with 32 µg/mL chloride being released

Results with reference substance:

The 4 bacterial strains (HK-3, HK-6, HK-8 and HK-10), grown on n-hexadecane, dechlorinated 1,10-dichlorodecane, 1-chlorobutane, 3-chlorobutyric acid and (for HK-10) 2-chloropropionic acid.

Applicant's summary and conclusion

Conclusions:

Significant dechlorination of Toyoparax 265 (a C12 chlorinated paraffin; 63% chlorination) in a cometabolic process has been demonstrated. Around 21% dechlorination was seen after 36 hours with a co-culture of four soil derived bacteria in the presence n-hexadecane.

Executive summary:

Co-metabolic degradation studies were carried out with Toyoparax 265 (a C12 chlorinated paraffin; 63% chlorination), at a concentration of chloride equivalent to 180 mg/1.2 L solution, using a mixed bacterial inoculum (strains HK-3, HK-6, HK-8 and HK-10) at 30^oC for 48 hours. The bacteria were isolated from soil using an enrichment culture containing n-hexadecane as sole carbon source.

Significant degradation was detected, with approx. 21% of the chloride being released after 36 hours, at which time bacterial growth and release of chloride ceased.