Dodecylbenzenesulphonic acid

Endpoint summary

Additional information

Environmental fate and pathways

 

Environmental exposure

 

Dodecylbenzenesulfonic acid is produced by reacting SO3 and LAB (linear alkyl benzene) in a continuous closed reactor. In the dodecylbenzenesulfonic acid reaction process, the measured concentrations of SO2, NaOH were 0.0026 and 0.0356 mg/m3, which were below the occupational exposure limit of 0.2 mg/m3 and 2 mg/m3, respectively. And the dust are emitted to atmosphere but the concentration of the substances were below 10% level of environmental emission standard (10 mg/m3).

All occurred waste organic solvents are burned by waste consignment treatment. Wastewater is treated chemically and biologically, and then it is discharged to wastewatertreatment plant. Most of the substance that is used in industrial and consumer products as surfactant and ingredient in detergents will be disposed of by the sewerage system. Exposure of the environment may occur mainly via effluents of STP’s and application of sewage sludge in agriculture.

 

Environmental fate

 

The environmental fate assessment for dodecylbenzene sulfonic acid (DDBSA) is based on US EPA’s Estimation Programs Interface (EPI) Suite. EPI Suite provides estimations of physical/chemical properties and environmental fate properties.

Based on the output of the model, dodecylbenzene sulfonic acid (DDBSA) is highly unlikely to bioaccumulate in the environment or aquatic organisms (i.e. fish) because the low value for the log Kow (4.78).

 This also supports that the chemical is soluble in water such that it will exhibit mobility through the soil. In addition, the low log Koc (3.6) further supports the expected soil mobility. The model-calculated linear and non-linear biodegradation probabilities suggest that the linear carbon chain will biodegrade rapidly, whereas the benzene ring is not expected to biodegrade as rapidly. The extremely low vapor pressure along with the short half life of approximately 7.85 hours indicates that if this chemical is present in the soil, it is not likely to be volatile and is expected to degrade rapidly.

The output parameters from the EPI Suite model support that any potential impacts of this chemical is expected to be very short-lived. This is because it is not likely to persist in water or microbial soils and sediments. As a result, the environmental fate of Dodecylbenzene sulfonic acid (DDBSA) is not likely to be of concern.

 

Hydrolysis will be not a significant factor in determining the environmental fate of dodecylbenzenesulfonic acid.

Based on the results, dodecylbenzenesulfonic acid was hydrolytically stable (half life > 1 year) specified by the OECD Guidelines. Since the chemical is degradable less than 10% after 5 days in this test condition, it is presumably stable in water. (Hydrolytically stable).

 Stability

 Phototransformation in air

 

Using the AOPWIN QSAR model, the photochemical degradation rate of Dodecylbenzenesulphonic acid in the atmosphere is16.3582 E-12 cm3/molecule-sec, with a resultant predicted half live of 7.846  Hrs (0.654 Days (12-hr day; 1.5E6 OH/cm3))

 

  OVERALL OH Rate Constant = 16.3582 E-12 cm3/molecule-sec

  HALF-LIFE =    0.654 Days (12-hr day; 1.5E6 OH/cm3)

  HALF-LIFE =    7.846 Hrs

 

Dodecylbenzenesulfonic acid has low vapor pressure (1.06E-008 Pa) indicating significant amounts of dodecylbenzenesulfonic acid are unlikely to be present in the atmosphere for photodegradation. The estimated half-life is about 7.8 hours (OH rate constant 16.36x10^-12cm³/ molecule-sec) with the AOPWIN (US EPA, 2011).

If released to air, a vapor pressure of 0.0000000000793 mm Hg at 25 deg C (0.0000000000793 mm Hg is equivalent to vapour pressure of 1.06E-008 Pa ) indicates significant amounts of dodecylbenzenesulfonic acid are unlikely to be present in the atmosphere for photodegradation and therefore Dodecylbenzenesulphonic acid 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.

Sodium dodecylbenzenesulfonate (CAS No.25155-30-0, EC Number; 246-680-4) is a very closeanalogue of the dissociated acid because it readily dissociates in water and release the dodecylbenzene sulfonic anion in solution.

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, Dodecylbenzenesulfonic acid is expected to have very high mobility based upon an estimated Koc of 2360. 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 .

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 Na-LAS) under aerobic and anaerobic conditions. Temmink and Klapwijk (2004) conducted OECD 301F test and the result is that more than 60% of mineralisation was achieved within 28 days.

For dodecylbenzene sulfonic acid, 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 dodecylbenzenesulfonic acid	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 dodecylbenzenesulfonic acid	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/l was measured>96% after 6 hours and 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% after 90 hours and test temperature was maintained at 24 deg 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

 

  

 Bioaccumulation

 

An estimated BCF is70.79 by BCFWIN Modelbased on log Kow =4.78(US EPA, 2011). Bioconcentrations of total C12-LAS in fathead minnows (Pimephales promelas), channel catfish (Ictalurus punctatus), and amphipod (Hyalella azteca) were investigated during 32 days. At 32 days, total C12-LAS bioconcentration factors (BCFs) for the three species ranged from 36 to 119 (Versteeg and Rawlings, 2003).These experimental and estimated BCF values suggest that dodecylbenzenesulfonic acid has a low potential for bioaccumulation.

 

 This substance has a limited potential to bioaccumulate (based on log Kow used by BCF estimates:4.78, and predicted bioconcentration factors, log BCF = 1.850 (EPIWIN/BCF Program).

The estimated BCF of 70.79 L/kg wet-wt was measured by calculation from EPI SuiteTM v4.1 Program.

These values would suggest very low bioaccumulation potential.

This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency).

 

BCFBAF Program (v3.01) Results:

==============================

SMILES : O=S(=O)(c1ccc(cc1)CCCCCCCCCCCC)O

CHEM  : Benzenesulfonic acid, dodecyl-

MOL FOR: C18 H30 O3 S1

MOL WT : 326.50

 

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)

 Biotransformation Half-Life (days) : 1.32 (normalized to 10 g fish)

 Log BAF (Arnot-Gobas upper trophic): 2.71 (BAF = 509 L/kg wet-wt)

 

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 4.78

 

Equation Used to Make BCF estimate:

  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)

  

  Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)

 

   

Bioaccumulation: terrestrial

 

This substance has a limited potential to bioaccumulate (based on log Kow used by BCF estimates:4.78, and predicted bioconcentration factors, log BCF = 1.850 (EPIWIN/BCF Program).

The estimated BCF of 70.79 L/kg wet-wt was measured by calculation from EPI SuiteTM v4.1 Program.

These values would suggest very low bioaccumulation potential.

This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency).

 

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

 Log BCF (regression-based estimate): 1.85 (BCF = 70.8 L/kg wet-wt)

 Biotransformation Half-Life (days) : 1.32 (normalized to 10 g fish)

 Log BAF (Arnot-Gobas upper trophic): 2.71 (BAF = 509 L/kg wet-wt)

 

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 4.78

 

Equation Used to Make BCF estimate:

  Log BCF = 1.85 (Ionic; 11 or more -CH2- groups)

 

   Estimated Log BCF = 1.850 (BCF = 70.79 L/kg wet-wt)

 

 

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE 

 Frag | 1 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0341

 Frag | 1 | Sulfonic acid / salt -> aromatic attach  | 0.0248 | 0.0248

 Frag | 1 | Alkyl substituent on aromatic ring       | 0.1781 | 0.1781

 Frag | 1 | Aromatic-CH2                             | -0.3365 | -0.3365

 Frag | 4 | Aromatic-H                               | 0.2664 | 1.0655

 Frag | 1 | Methyl [-CH3]                           | 0.2451 | 0.2451

 Frag | 10 | -CH2- [linear]                          | 0.0242 | 0.2419

 Frag | 1 | Benzene                                  | -0.4277 | -0.4277

 L Kow| * | Log Kow =  4.78 (KowWin estimate)       | 0.3073 | 1.4704

 MolWt| * | Molecular Weight Parameter               |        | -0.8372

 Const| * | Equation Constant                        |        | -1.5058

============+============================================+=========

  RESULT  |       LOG Bio Half-Life (days)           |        | 0.1213

  RESULT  |           Bio Half-Life (days)           |        |  1.322

  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |

============+============================================+=========

 

Biotransformation Rate Constant:

 kM (Rate Constant): 0.5242 /day (10 gram fish)

 kM (Rate Constant): 0.2948 /day (100 gram fish)

 kM (Rate Constant): 0.1658 /day (1 kg fish)

 kM (Rate Constant): 0.09322 /day (10 kg fish)

 

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

  Estimated Log BCF (upper trophic) = 2.704 (BCF = 506 L/kg wet-wt)

  Estimated Log BAF (upper trophic) = 2.707 (BAF = 508.9 L/kg wet-wt)

  Estimated Log BCF (mid trophic)  = 2.806 (BCF = 639.2 L/kg wet-wt)

  Estimated Log BAF (mid trophic)  = 2.828 (BAF = 673.4 L/kg wet-wt)

  Estimated Log BCF (lower trophic) = 2.831 (BCF = 677.5 L/kg wet-wt)

  Estimated Log BAF (lower trophic) = 2.911 (BAF = 814 L/kg wet-wt)

 

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

  Estimated Log BCF (upper trophic) = 3.729 (BCF = 5355 L/kg wet-wt)

  Estimated Log BAF (upper trophic) = 4.670 (BAF = 4.677e+004 L/kg wet-wt)

 

    

Transport and distribution

Adsorption / desorption

 

The log of the adsorption coefficient (KOC) of LAS-C12 was estimated to be log KOC = 3.21 which is equal to a KOC value of 2360 . Sodium dodecylbenzenesulfonate (CAS No. 25155-30-0) is a very close analogue of the dissociated acid because it readily dissociates in water and release the dodecylbenzene sulfonic anion in solution.

The log of the adsorption coefficient (KOC) ofDodecylbenzenesulphonic acidwas estimated to be log KOC =3.5691which is equal to a KOC value of 3707 using the KOCWIN v2.00 QSARmethod.

KOCWIN Program (v2.00) Results:

==============================

SMILES : O=S(=O)(c1ccc(cc1)CCCCCCCCCCCC)O

CHEM  : Benzenesulfonic acid, dodecyl-

MOL FOR: C18 H30 O3 S1

                

--------------------------- KOCWIN v2.00 Results ---------------------------

 

 Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index ........... : 10.537

        Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 6.0928

        Fragment Correction(s):

                 1  Sulfonic acid (-S(=O)-OH) ............. : -2.0000

        Corrected Log Koc .................................. : 4.0928

 

                        Estimated Koc: 1.238e+004 L/kg  <===========

 

 Koc Estimate from Log Kow:

 -------------------------

        Log Kow (Kowwin estimate) ......................... : 4.78

        Non-Corrected Log Koc (0.55313 logKow + 0.9251) .... : 3.5691

        Fragment Correction(s):

                 1  Sulfonic acid (-S(=O)-OH) ............. : 0.0000

        Corrected Log Koc .................................. : 3.5691

 

                        Estimated Koc: 3707 L/kg  <===========

 

 

 Henry's Law constant

 

The estimated Henrys Law Constant (25 deg C) measured by calculation from EPI SuiteTM v4.1, HENRYWIN v3.20 Program was 6.27E-008 atm-m3/mole (6.35E-003 Pa-m3/mole) , which is almost zero.

This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency).

 

Distribution modelling.

 

Dodecylbenzenesulphonic acid has no affinity to be in air and sediment. The direct emissions to soil and surface water are significant, therefore Dodecylbenzenesulphonic acid will be almost exclusively be found in soil and surface water.

 

 Mackay fugacity modelling (level 3) indicates that, taking into account degradation and using inflow parameters which are consistent with the known production tonnage of this substance in, fugacity coefficient indicates that environmental concentrations in water are predicted to be 3.24e-013  (atm), in air (atm) 2.53e-014  and soil 4.92e-014   (atm) and sediment to be  2.03e-013  (atm).

These are negligible low levels. This can be considered a worse case prediction as it assumes all product is emitted with no emission control systems used.

    

Other distribution data

 

These results suggest for Dodecylbenzenesulphonic acid that direct and indirect exposure from distribution in media is unlikely.

Based on low vapor pressure and low estimated log Pow, expected to partition to water and soil. Not expected to partition to air, sediments or biota.

 

Therefore testing for distribution in media does not need to be performed.

 

The estimated STP Fugacity Model and Volatilization From Water were measured by calculation from EPI SuiteTM v4.1 Program.

This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency) .

 

                                              Volatilization From Water

                                       =========================

 

Chemical Name: Benzenesulfonic acid, dodecyl-

 

Molecular Weight   : 326.50 g/mole

Water Solubility      : 9.1359 mg/l

Vapor Pressure      : 1.06E-008 Pa at 25C.

Henry's Law Constant: 6.27E-008 atm-m3/mole (estimated by Bond SAR Method)

 

                                               RIVER            LAKE

                                              ---------        ---------

Water Depth    (meters):              1                1         

Wind Velocity   (m/sec):              5                0.5       

Current Velocity (m/sec):            1                0.05      

 

     HALF-LIFE (hours) :  1.687E+004       1.842E+005

     HALF-LIFE (days ) :   703.1                   7677      

     HALF-LIFE (years) :   1.925                   21.02     

 

 

STP Fugacity Model: Predicted Fate in a Wastewater Treatment Facility

=====================================================

                       (using 10000 hr Bio P,A,S)

PROPERTIES OF: Benzenesulfonic acid, dodecyl-

 

Molecular weight (g/mol)                              326.5

Aqueous solubility (mg/l)                               0

Vapour pressure (Pa)                                     0

               (atm)                                               0

               (mm Hg)                                         0

Henry 's law constant (Atm-m3/mol)        6.27E-008

Air-water partition coefficient                    2.56424E-006

Octanol-water partition coefficient (Kow)    60256

Log Kow                                                          4.78

Biomass to water partition coefficient       12052

Temperature [deg C]                                    25

Biodeg rate constants (h^-1),half life in biomass (h) and in 2000 mg/L MLSS (h):

         -Primary tank        0.00     9601.66      10000.00

         -Aeration tank      0.00     9601.66      10000.00

         -Settling tank        0.00     9601.66      10000.00

 

                                         STP Overall Chemical Mass Balance:

                                                 ---------------------------------

                                                     g/h              mol/h             percent

 

Influent                                  1.00E+001        3.1E-002       100.00

 

Primary sludge                       4.24E+000        1.3E-002       42.42

Waste sludge                         2.65E+000        8.1E-003       26.49

Primary volatilization           1.00E-005         3.1E-008        0.00

Settling volatilization            2.45E-005         7.5E-008       0.00

Aeration off gas                    6.03E-005         1.8E-007        0.00

 

Primary biodegradation          1.29E-002         4.0E-005         0.13

Settling biodegradation           3.47E-003         1.1E-005         0.03

Aeration biodegradation         4.57E-002         1.4E-004         0.46

 

Final water effluent                 3.05E+000        9.3E-003         30.47

 

Total removal                        6.95E+000        2.1E-002         69.53

Total biodegradation             6.21E-002         1.9E-004         0.62