LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
4.4 TOXICITY TO BACTERIA
(a)
Type: Aquatic [X]; Field [ ]; Soil [ ]; Other [ ]
Species: activated sludge
Exposure Period: 3 hour
Results: EC50 (Na LAS-C11) = 760 mg/L
EC50 (Na LAS-C11.6) = 550 mg/L
EC50 (Na LAS-C13) = 650 mg/L
Analytical monitoring: Yes [ ] No [X] ? [ ]
Method: OECD 209 Activated Sludge Respiration Inhibition Test. 1984.
GLP: Yes [X] No [ ] ? [ ]
Test substance: Three different alkyl chain lengths of LAS (C11, C11.6, C13 sodium salts), with
the following homologue distributions.
Alkyl Chain Length Distributions (%)
LAS C11 LAS C11.6 LAS C13
C14 -- -- 0.3
LAS MW
(as Na-LAS)
334 343 363
Remarks: The purpose of the study was to determine the toxicity of three commercial
LAS products to the activated sludge of a treatment plant basically operating
on domestic sewage. A contact time of 3 hours instead of 15 minutes was
chosen to better simulate the real residence time used in wastewater
treatment plants (4-6 hours). The EC50 values are far above environmental
concentrations and therefore provide a high margin of safety. The 3-hour
EC50 range for the reference substance (3,5-dichlorophenol) ranged from 20-
30 mg/L, within the valid range of 5-30 mg/L.
Reference: Verge C. and Moreno, A. 1996b. Toxicity of anionic surfactants to the
bacterial population of a waste water treatment plant. Tenside Surf. Det.
33:323-327.
Reliability: 2 Valid with restrictions
(b)
Type: Aquatic [X]; Field [ ]; Soil [ ]; Other [ ]
Species: activated sludge
Exposure Period: 3 hour
Results: EC50 (Na LAS-C10) = 1042-1200 mg/L
EC50 (Na LAS-C11) = 740-782 mg/L
EC50 (Na LAS-C12) = 500-723 mg/L
EC50 (Na LAS-C13) = 700-795 mg/L
EC50 (Na LAS-C14) = 900-1045 mg/L
Analytical monitoring: Yes [ ] No [X] ? [ ]
Method: OECD 209 Activated Sludge Respiration Inhibition Test. 1984.
GLP: Yes [X] No [ ] ? [ ]
Test substance: Five different pure homologues of LAS (C10, C11, C12, C13, C14 sodium salts),
with the following homologue distributions.
UNEP PUBLICATIONS 198