Benzenesulfonic acid, 4-C10-13-sec-alkyl derivs.

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP laboratory study

Qualifier:

according to guideline

Guideline:

other: OECD DOC-Die away test (EG-Richtlinie 92/69 EWG, Tiel II, C.4-A)

Principles of method if other than guideline:

Equivalent to OECD 301A

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

28 d

Initial conc.:

11.3 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

A measured volume of inoculated mineral medium, containing a known concentration of the test substance (10-40 mg DOC/l) as the nominal sole source of organic carbon, is aerated in the dark or diffuse light at 22 ± 2°C. Degradation is followed by DOC analysis at frequent intervals over a 28-day period. The degree of biodegradation is calculated by expressing the concentration of DOC removed (corrected for that in the blank inoculum control) as a percentage of the concentration initially present.

Reference substance:

benzoic acid, sodium salt

Remarks:

99.5% purity

Key result

Parameter:

% degradation (DOC removal)

Value:

94

Sampling time:

28 d

Details on results:

readily biodegradable

Results with reference substance:

Biodegradation with the reference substance, sodium benzoate, at 11.8 mg DOC/L resulted in 96% degradation in 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Executive summary:

The substance was tested in a 28 -day DOC-die away test and found to be degraded by 94% in 28 days. The substance is readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Nov. 18, 2002-Dec. 19, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Marl-Ost municipal sewage treatment plant
- Initial cell/biomass concentration: 3.94 g/l dry matter

Duration of test (contact time):

29 d

Initial conc.:

34.3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Test temperature: 19.7-21.9 degree C
- pH: 7.4-7.5
- Aeration of dilution water: yes, overnight
- Suspended solids concentration: 26.3 mg/L

TEST SYSTEM
- Culturing apparatus: 5000 ml Woullf flasks
- Number of culture flasks/concentration: 2 flasks

SAMPLING
- Sampling frequency: 0, 2, 5, 9, 12, 14, 21, 28, and 29 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 flasks

STATISTICAL METHODS: Results were calculated using the EXCEL computer program.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

85

Sampling time:

29 d

Details on results:

The test substance was 85% degraded on day 29.

Results with reference substance:

The reference substance was 89% degraded in 29 days.

% Degradation

Test Duration (days)	Sodium Benzoate	Test Vessel 1	Test Vessel 2	Test Vessel Mean
0	0	0	-1	-1
2	32	1	-5	-2
5	59	24	19	22
9	76	57	46	52
12	84	73	66	70
14	84	72	67	70
21	93	76	79	78
28	95	86	80	83
29	89	84	85	85

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test substance was 85% degraded in 29 days, and is considered readily biodegradable.

Executive summary:

This study examined the biodegradability of the test substance. 34.3 mg/L of test substance was added to flasks containing activated sludge. The amount of CO2 evolved was then measured over the next 29 days. Sodium benzoate was used as a reference substance. The reference substance was 89% degraded in 29 days. Therefore the test is valid. The test substance was 85% degraded in 29 days. The test substance is readily biodegradable.

Description of key information

The key study examined the biodegradability of LAS-acid. The substance (initial concentration at 11.3 mg/L DOC) was tested in a 28 -day DOC-die away test and found to be degraded by 94% in 28 days. The substance is readily biodegradable. The supporting study examined the biodegradability of LAS. The amount of CO2 evolved was measured over 29 days. The test substance was 85% degraded in 29 days. The reference substance (sodium benzoate) was 89% degraded in 29 days. Thus, the LAS is readily biodegradable as well.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable