Calcium dodecylbenzenesulphonate

Biodegradation in soil

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in soil: simulation testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Sodium dodecylbenzenesulfonate (CAS# 25155-30-0 , EC Number; 246-680-4 ) is a very close analogue of Calcium dodecylbenzenesulfonate (CAS No 26264-06-2, EC Number; 247-557-8) ) and read-across is valid.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

GLP compliance:

not specified

Test type:

laboratory

Radiolabelling:

yes

Oxygen conditions:

aerobic/anaerobic

Soil classification:

other: Alfisol

Details on soil characteristics:

- Soil : Air-dried and sifted to a particle size of 0.125 mmparticle size distribution ; Clay(<2 μm) 17%, silt(2-63 μm) 75%, sand(0.63-2 mm) 8%, organic matter 2.45%- Soil pH : 7.3

Initial conc.:

15 other: μg

Based on:

test mat.

Details on experimental conditions:

- Experience vessels; 1 litre wide-mouth bottles- Incubation mixture; 50g soil and 150ml water were equilibrated for 7 days at 35 deg C in oxygen or nitrogen. Then 15μg of 14C-labelled chemical was added in aqueous solution ot suspension.- Mechnical mixing; continuous shaking in a water bath (35 deg C)

% Degr.:

40.6 - 51.9

Parameter:

CO2 evolution

Sampling time:

42 d

Transformation products:

yes

Conclusions:

n-Dodecylbenzenesulphonate was readily biodegradable. And the degradation (mineralization) values in anaerobic environment was faster than those in aerobic environment.

Reference 2

Endpoint:

biodegradation in soil: simulation testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

C12 LAS; Linear Alkylbenzene Sulfonate (LAS)) is a very close analogue of Calcium dodecylbenzenesulfonate (CAS No 26264-06-2, EC Number; 247-557-8) ) and read-across is valid.

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

GLP compliance:

not specified

Test type:

laboratory

Radiolabelling:

yes

Soil classification:

other: : Soil type in Rapid city is the sandy loam and soil type in Harleysville is the loamy sand.

Details on soil characteristics:

Soils were obtained from sludge-amended agricultural fields in Rapid city and Harleysville. Soil type in Rapid city is the sandy loam and soil type in Harleysville is the loamy sand.

Initial conc.:

250 mg/kg soil d.w.

Based on:

test mat.

Soil No.:

#1

Temp.:

20℃

Humidity:

35% moisture level

Details on experimental conditions:

Tesk flasks were continuously flushed with CO2-free air at >>50ml/min and incubated 20 +/- 2 deg C. Half-lives ofr mineralization(t 1/2) were calculated from the relationship t 1/2=ln2/k1(k1=first-order rate conctant).

DT50:

23.1 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20 °C

Transformation products:

yes

Details on results:

Half-lives for mineralization of the C12-LAS homolog is 23.1 days.

Conclusions:

Half-lives for mineralization of the C12-LAS homolog is 23.1 days.

Description of key information

Biodegradation in soil
 
Ward and Larson (1989) conducted a laboratory study and observed the biodegradation rate constant and half-life for C12-LAS in sludge-amended soil. The biodegradation rate constant for C12-LAS is 0.030 day-1and half-life for C12-LAS is 23.1 days. Scheunertet al., (1987) measured the biomineralization rate of dodecylbenzenesulfonate in soil/water suspension under anaerobic and aerobic conditions for 42 days. The results (40.6%14CO2: aerobic, 51.9%14CO2: anaerobic) showed that the substance was readily biodegradable by the micro-organisms present in soil.

Key value for chemical safety assessment

Half-life in soil:

23.1 d

at the temperature of:

20 °C

Additional information

Biodegradation in soil

 

Ward and Larson (1989) conducted a laboratory study and observed the biodegradation rate constant and half-life for C₁₂-LAS in sludge-amended soil. The biodegradation rate constant for C₁₂-LAS is 0.030 day^-1and half-life for C₁₂-LAS is 23.1 days. Scheunertet al., (1987) measured the biomineralization rate of dodecylbenzenesulfonate in soil/water suspension under anaerobic and aerobic conditions for 42 days. The results (40.6%¹⁴CO₂: aerobic, 51.9%¹⁴CO₂: anaerobic) showed that the substance was readily biodegradable by the micro-organisms present in soil.

 

Table     Summary of Biodegradationin soil

 

Type/ Method	Test material	Degradation	Duration	References
Aerobic/ Other	C12-LAS	50%	23.1 days	Ward and Larson, 1989
Aerobic and Anaerobic/ Other	Dodecylbenzenesulfonate	40.6%^14CO2of mineralization (aerobic), 51.9%^14CO2of mineralization (anaerobic)	42 days	Scheunertet al., 1987