LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
The BCFs were 87 L/kg for a standard mixture typical of LAS in European
detergent formulations (average alkyl chain length = C11.6) and 22 L/kg for a
representative environmental sample (filtered Mississippi river water,
average alkyl chain length = C10.8), indicating that the bioconcentration
potential of LAS is low and is decreased by environmental processes such as
biodegradation and absorption, which reduce aquatic concentrations.
Reference: Tolls, J., Haller, M., DeGraaf, I., Thijssenk, M.A.T.C. and Sijm, D.T.H.M.
1997. Bioconcentration of LAS: Experimental determination and
extrapolation to environmental mixtures. Environ. Sci. Technol. 31:3426-
3431.
Reliability: 2 Valid with restrictions
(b)
Species: Lepomis macrochirus
Exposure Period: 21 days
Temperature: 17 + /-1 o C
Concentration: 0.5 mg/L
BCF: 104 (whole body); 36 (muscle)
Elimination: Yes
Method: Bluegill sunfish (avg wt. 4.0 g; avg length 68 mm) were placed in a 60 liter
aquarium (375 fish total) and maintained for 21 days. A second aquarium
held 100 control fish. Fish were fed daily with a dry pelleted trout chow
ration of approximately 2% of body weight. Water samples were removed
periodically for radiometric analysis of 14 C-labeled LAS. Four fish were
removed on each of days 1, 2, 3, 5, 7, 9, 11 and 14 for radiometric analysis.
Type of test: calculated [ ]; measured [ ]; static [ ]; semi-static [ ]; flow-through [X]
GLP: Yes [ ] No [ ] ? [X]
Test substance: C10-13 LAS (CAS #68411-30-3) with the following alkyl chain length
distribution: C11 45%, C12 36.5%, C13 18.5%. Average chain length was 11.7
and molecular weight was 344.
Remarks: The site of greatest concentration was the gall bladder with a BCF of 5000,
based on total radiolabeled materials. The BCFs for liver, gills and viscera,
remaining carcass, and blood ranged from 64 to 283. Clearance of
radiolabeled materials was rapid with half-lives of 2 to 5 days. However, no
quantitative conclusions specific to LAS can be drawn from these data, as
total radiolabeled materials were measured, and these likely include LAS
metabolites.
Reference: Kimerle, R.A., Macek, K.J., Sleight, B.H. and Burrows, M.E. 1981.
Bioconcentration of linear alkylbenzene sulfonate (LAS) in bluegill
(Lepomis macrochirus). Wat. Res. 15:251-256.
Reliability: 2 Valid with restrictions
3.8 ADDITIONAL REMARKS
A. Sewage treatment
(a)
Results: LAS removal in sewers due to biodegradation can reach as high as 50% of
the total LAS load when the sewer system is properly aerated.
Method: Integrated composite samples were collected in November and December
1988 from the sewer system of Estepona (Malaga), Spain. LAS was
analyzed using a specific HPLC technique.
UNEP PUBLICATIONS 171