LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Results: The 72-hr EC50 values were 270, 111, 48, 30, and 18 mg/L for pure
homologues C10, C11, C12, C13, and C14, respectively. The corresponding
NOEC values were 80, 40, 18, 12, and 7, respectively.
Analytical monitoring: Yes [ ] No [X] ? [ ]
Method: OECD 201 Algal growth inhibition test. 1984. The test media recommended
by AFNOR was used. All water quality parameters were maintained within
acceptable ranges in compliance with the test protocol. Initial cell
concentrations were 1 x 10 4 cells/mL. Final cell counts not reported.
open-system [X]; closed-system [ ]
GLP: Yes [X] No [ ] ? [ ]
Test substance: Five pure homologue cuts were tested, with the following distribution.
Alkyl Chain Length Distributions (%)
LAS C10 LAS C11 LAS C12 LAS C13 LAS C14
C14 -- -- -- -- 0.9
LAS MW
(as Na-LAS)
320.7 333.7 346.4 362.3 373.7
Remarks: French strain of S. subspicatus from the University of Metz. As NOEC (no
observed effect concentration), the authors used the EC5 because of the lack
of noticeable variation in toxicity for the interval 0-5%. This is a key study
for aquatic toxicity to algae (see SIAR Table 12).
Reference: Verge, C. and Moreno, A. 1996a. Toxicity of anionic surfactants to
green microalgae “Scenedesmus subspicatus” and “Selenastrum capricornutum.” Tenside
Surf. Det. 33:166-168.
Reliability: 2 Valid with restrictions
(f)
Species: Scenedesmus subspicatus (Algae)
Endpoint: Biomass [X]; Growth rate [X]; Other [ ]
Exposure period: 72 hour
Results: ErC50 (growth rate) = 127.9 mg/L; EbC50 (biomass) = 43.2 mg/L
NOEC (growth rate) = 2.4 mg/L; NOEC (biomass) = 2.2 mg/L
LOEC (growth rate) = 10 mg/L
Inhibition of cell growth by concentration and duration is shown in the table
below:
Cell number ( x 10 4 cells/mL)
Time Period (hours)
Test concentration
0 24 48 72
(mg/L)
Control 2 8 29 95
0.6 2 8 30 89
2.4 2 9 28 85
10 2 9 27 75
40 2 8 20 48
160 2 7 9 8
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