Sodium dodecylbenzenesulfonate

Endpoint summary

Additional information

 

Stability

 

Phototransformation in air

  

Using the AOPWIN QSAR model, the photochemical degradation rate of Sodium dodecylbenzenesulfonate in the atmosphere is 16.2182 E-12 cm3/molecule-sec, with a resultant predicted half live of  7.914 Hrs ( 0.660 Days (12-hr day; 1.5E6 OH/cm3))

   

  OVERALL OH Rate Constant = 16.2182 E-12 cm3/molecule-sec

  HALF-LIFE =    0.660 Days (12-hr day; 1.5E6 OH/cm3)

  HALF-LIFE =    7.914 Hrs

 

   

Sodium dodecylbenzenesulfonate has low vapor pressure (3.05E-013Pa) indicating significant amounts of Sodium dodecylbenzenesulfonate are unlikely to be present in the atmosphere for photodegradation. The estimated half-life is about 7.9.14 hours (OH rate = 16.2182 E-12 cm3/ molecule-sec) with the AOPWIN (US EPA, 2011).

  

If released to air, a vapor pressure of 2.29E-015 mm Hg at 25 deg C ( 2.29E-015 mm Hg is equivalent to vapour pressure of 3.05E-013Pa) indicates significant amounts of Sodium dodecylbenzenesulfonate are unlikely to be present in the atmosphere for photodegradation and therefore Sodium dodecylbenzenesulfonate is not expected to be susceptible to direct photolysis by sunlight.

 

   

Phototransformation in water

 

After 30 minutes the Sodium dodecylbenzenesulfonate (DBS) have been decomposed and removal of the DBS absorption is complete after 2 hours of the light exposure.Rapid photodegradation (within 2 hours of light exposure) .

Dodecylbenzene sulfonate is rapidly photodegraded in aqueous aerated TiO2 suspensions. The reaction involves fast decomposition of the aromatic ring followed by slower oxidation of the aliphatic chain.

Data are available on the photodegradation of Na-C12 LAS in water.

The results are as follows:

Table   Photodegradations of Na-C12 LAS

Light source	Light spectrum	Test material	Result	References
Xe lamp	>330 nm	Sodium dodecylbenzenesulfonate	Rapid (<1-2 hours) decomposition	Hidakaet al., 1985
Mercury vapor lamp	200-350 nm	Sodium dodecylbenzenesulfonate	>95% photolytic degradation after 20 minutes	Matsuura and Smith, 1970
Mercury lamp	400-580 nm	Sodium dodecylbenzenesulfonate	The presence of humic substances delayed the photodegradation	Hermannet al., 1997

 

 

Phototransformation in soil

If released to soil, Sodium dodecylbenzenesulfonate is expected to have very high mobility based upon an estimated Koc of 102.1. Volatilization from moist soil surfaces is not expected to be an important fate process.

Therefore testing for Phototransformation in soils does not need to be performed.

 

Hydrolysis

 

Hydrolysis is a chemical reaction during which molecules of water (H2O) are split into hydrogen cations (H+, conventionally referred to as protons) and hydroxide anions (OH−) in the process of a chemical mechanism).

The study of MOE 2008 was performed following “OECD Guidelines for Testing of Chemicals No. 111: Hydrolysis as function of pH. The preliminary test was performed at 50 ±5°C and pH 4, 7 and pH 9. The hydrolysis of the substance was less than 10% over the 5 days, so a definitive test was not performed. Based on these results, dodecylbenzenesulfonic acid was hydrolytically stable (half life > 1 year) specified by the OECD Guidelines .Dodecylbenzene sulfonic acids (CAS# 27176-87-0 , EC Number; 248-289-4) ) is a very close analogue of Sodium dodecylbenzenesulfonate (CAS No. 25155-30-0, EC Number; 246-680-4) ) and the dissociated acid it readily dissociates in water and release the dodecylbenzene sulfonic anion in solution .

Since the chemical is degradable less than 10% after 5 days in this test condition, it is presumably stable in water. (Hydrolytically stable)

 

 Biodegradation

 

Data of following studies are demonstrating rapid biodegradation of C12-LAS (including sodium dodecylbenzene sulfonate (DBS)) under aerobic and anaerobic conditions. Temmink and Klapwijk (2004) conducted OECD 301F test and the result is that more than 60% of mineralisation was achie

Biodegradation of sodium dodecylbenzene sulfonate (DBS), at 10 ppm was measured 75% after 11 days and test temperature was maintained at 20 deg C for 17 days. The sodium dodecylbenzene sulfonate (DBS) could be conclued as readily degradable.ved within 28 days.

For dodecylbenzene sulfonic acid (Dodecylbenzene sulfonic acids (CAS# 27176-87-0 , EC Number; 248-289-4) ) is a very close analogue of Sodium dodecylbenzenesulfonate (CAS No. 25155-30-0, EC Number; 246-680-4) ) and the dissociated acid it readily dissociates in water and release the dodecylbenzene sulfonic anion in solution.), the available study indicates 69% of the material mineralized after 28 days ,OECD 301B test (USEPA 1992).

 

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.

 

Summary of Biodegradation

 

Type/ Method	Test material	Degradation	Duration	References
Aerobic/ OECD 301F	C12-LAS	> 60 % of mineralisation	28 days	Temmink and Klapwijk, 2004
Aerobic/ Other	Sodium dodecylbenzenesulfonate	75 %	11 days	Cook and Glodman, 1974
Aerobic/ OECD 301B	Dodecylbenzenesulfonic acid	69 % of mineralisation	28 days	USEPA 1992
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

 

    

 

Biodegradation in water:screening tests

Data of following studies are demonstrating rapid biodegradation of C12-LAS (including Na-LAS) under aerobic conditions. Temmink and Klapwijk (2004) conducted OECD 301F test and the result is that more than 60% of mineralisation was achieved within 28 days.

Cook and Glodman, 1974 conducted Biodegradation of sodium dodecylbenzene sulfonate (DBS), at 10 ppm was measured 75% after 11 days and test temperature was maintained at 20 deg C for 17 days. The sodium dodecylbenzene sulfonate (DBS) could be conclued as readily degradable.

For dodecylbenzene sulfonic acid, the available study indicates 69% of the material mineralized after 28 days ,OECD 301B test (USEPA 1992).

  

Table     Summary of Biodegradation in water:screening tests

 

Type/ Method	Test material	Degradation	Duration	References
Aerobic/ OECD 301F	C12-LAS	> 60 % of mineralisation	28 days	Temmink and Klapwijk, 2004
Aerobic/ Other	Sodium dodecylbenzenesulfonate	75 %	11 days	Cook and Glodman, 1974
Aerobic/ OECD 301B	Dodecylbenzenesulfonic acid	69 % of mineralisation	28 days	USEPA 1992

 

  

Biodegradation in water and sediment: simulation tests

 

In the study of Federle TW and Itrich NR 1997, Linear alkylbenzene sulfonate (14C-ring C12LAS) was tested as model compounds in two sludges.

-        Within 8 h, 41−44% was evolved as 14CO2,

-        1−2% remained as parent,

-        24−33% was incorporated into biomass,

-        and 10−15% was present as intermediates, primarily sulfophenylcarboxylates.

 Primary and complete biodegradation were best described by a first-order model. First-order rate constants for LAS were 0.96−1.10 h-1 for primary loss and 0.50−0.53 h-1 for complete degradation. This approach provides an accurate and comprehensive kinetic picture of biodegradation under realistic conditions as well as information on the mechanism of biodegradation.

Biodegradation of Linear alkylbenzene sulfonate (14C-ring C12LAS), at 1mg/lwas measured>96% after6hoursand test temperature was maintained at 20 deg C.

 

In the study of Kubodera T, Muto T and Yamamoto T 1978 Dodecylbenzenesulfonate 14C (DBS-14C) was tested as model compound.

Biodegradation of Dodecylbenzenesulfonate 14C(DBS-14C)at76ppmwas measured>90% after90hoursand test temperature was maintained at 24deg C.

DBS decreased from 76.0 ppm to less than 0.6 ppm at 90h (Readily degradation).The biodegradation of DBS-14C has three periods of rapid adsorption period, acclimation period, and degradation process. 1-Tetralone, 1-indanone, 4-methyl-1-tetralone, naphthalene were the decomposition products

 

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