LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
a NOEC of 319.0 ppm (LOEC = 993 ppm). This indicates that sorption onto
sediment significantly mitigates LAS bioavailability. Thus, the water-only
values above should be considered conservative. This is a critical study for
this SIDS endpoint.
Reference: Pittinger, C.A., Woltering, D.M., and Masters, J.A. 1989. Bioavailability of
sediment-sorbed and aqueous surfactants to Chironomus riparius (midge).
Environ. Toxicol. Chem. 8:1023-1033.
Reliability: 2 Valid with restrictions.
Water and Sediment Exposures
(p)
Type of Test: Semi-static
Species: Anodonta cygnea (fresh water bivalve mollusc)
Endpoint: Mortality [X]; Reproduction rate [ ]; Other [ ] growth, reproduction
Exposure period: 80 days
Results: NOEC ≥ 200 mg/kg dw
Analytical monitoring: Yes [X] No [ ] ? [ ]
Method: Sediments were collected from a pond and LAS was sorbed to sediment by
repeated additions for 80 days. Glass tanks containing a 4 cm thick layer of
spiked sediment and eight liters of dechlorinated tap water were used. A
continuous water exchange allowed for a whole water mass change every 24
hours. Ten bivalves (10 + /-1 cm or larger diameter) were introduced into each
tank. The LAS sorbed to sediment was 750 mg/kg dw at the beginning of
the experiment and 200 mg/kg dw at the end of the experiment.
GLP: Yes [ ] No [ ] ? [X]
Test Substance: Commercial LAS (unspecified)
Remarks: All animals survived the 80 day exposures and were actively filter-feeding
without differences from the controls.
Reference: Bressan, M., Brunetti, R., Casellato, S., Fava, G.C., Giro, P., Marin, M.,
Negrisolo, P., Tallandini, L., Thomann, S., Tosoni, L., Turchetto, M. and
Campesan, G.C. 1989. Effects of linear alkylbenzene sulfonate (LAS) on
benthic organisms. Tenside Surf. Det. 26:148-158.
Reliability: 2 Valid with restrictions (no GLP, statistical methods not described)
(q)
Type : Artificial soil [ ]; Filter paper [ ]; Other [X] Natural sediment
Species: Branchiura sowerbyi (tubificid worm)
Endpoint: Mortality [ ]; Weight [ ]; Other [X] Reproductive Cycle
Exposure period: 220 days
Results: NOEC ≥ 7.18 mg/kg.
Mean measured LAS concentrations in the sediment were 26, 9.8, and 7.18
mg/kg at 0, 45, and 220 days of exposure. No significant differences were
observed between treated and control sediments for any parameter (survival,
timing and percentage of cocoons, percent of hatching worms, number of
eggs per cocoon, and mean embryonic development time). Total number of
cocoons was slightly higher in treated worms than cocoons.
Method: Twenty specimens in duplicate were used for both the control and treated
sediments for testing the possible effects of a long exposure to LAS adsorbed
on sediment to oligochaetes. Worms with a well known reproductive cycle
were collected and maintained in the dark at 15ºC in a glass container with
natural sediment for at least two weeks before the experiment. The sediment
for the experiments was gently washed with deionized water and dried at
70ºC. It was organized by grain size, carbonate and organic carbon contents.
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