LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
cake. Standard acute toxicity tests were also conducted in the laboratory.
Statistical analysis was done using F and t tests and the significance of any
change was measured at a 5% level of probability.
GLP: Yes [ ]; No [X]; ? [ ]
Test Substance: LAS (Parnol J Liquid), 20% activity; clear yellow liquid; pH in solution was
8 ± 1
Remarks: The feeding rates decreased significantly at 0.25, 0.38 and 1.10 mg/L. Fish
showed erratic behaviour, irregular opercular movement, and at higher
concentrations, blood exuded from the base of the pectoral and pelvic fins
and head. No apparent difference in condition factor (K) was observed at any
concentration. The maturity index (MI) of both male and female fish
appeared to decrease at all concentrations, but the biological significance of
this is questionable because historic control values for this parameter were
not provided and the magnitude of the response did not increase with dose.
Fecundity decreased at 0.51 mg/L but not at 1.10 mg/L. The gastrosomatic
index (GSI) was significantly different at 0.51 and 1.10 mg/L. Based on the
most reliable endpoints (GSI and fecundity), the NOEC would be 0.38 mg/L
and the LOEC would be 0.51 mg/L. However, the study is incompletely
documented, so details of the test substance composition and testing
procedure are uncertain. True replicates were not used so statistics can not be
validly conducted, though they are reported by the authors. In view of these
limitations, and previous evaluations of the study which have reported a
NOEC of 0.25 mg/L (van de Plassche et al., 1999), a conservative
(protective) NOEC for this study is 0.25 mg/L. This is a critical study for this
SIDS endpoint.
Reference: Chattopahyay, D.N. and Konar, S.K. 1985. Acute and chronic effects of
linear alkyl benzene sulfonate on fish, plankton, and worm. Environment &
Ecology, 3:258-262.
Reliability: 2 Valid with restrictions.
(f)
Type of test: Various types and durations of tests.
Results: The article compiles the no observed effect concentration (NOEC) values for
many tests conducted on an assortment of species. The following table
shows the geometric mean NOEC values for each fish species (n = number of
studies included for each species).
Species Geometric mean
NOEC (mg/L)
N
Brachydanio rerio 2.3 1
Pimephales promelas 0.87 14
Poecilia reticulate 3.2 1
Oncorhynchus mykiss 0.34 7
Tilapia mossambica 0.25 1
Remarks: All data were from tests conducted on commercial LAS with C10-13 alkyl
chains and average carbon lengths close to C11.6 and C11.8. The NOEC values
have been normalized using QSARs to the average structure of C11.6 LAS.
Reference: van de Plassche, E.J., DeBruijn, J.H.M., Stephenson, R.R., Marshall, S.J.,
Feijtel, T.C.J., and Belanger, S.E. 1999. Predicted no-effect concentrations
and risk characterization of four surfactants: Linear alkyl benzene sulfonate,
alcohol ethoxylates, alcohol ethoxylated sulfates, and soap. Environ.
Toxicol. Chem. 18: 2653-2663.
Reliability: 4 Not assignable This study was given a reliability score of 4 because the
original reports reviewed by the authors were not directly reviewed in the
compilation of this robust summary.
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