LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
sorption period. The sand was then mixed with sludge (0.3 g dry weight) and
finally soil was mixed in with the sludge and sand. A sludge:soil ratio of
1:100 (dry weight basis) was used to avoid depletion of oxygen.
Folsomia candida
The springtail reproduction test was initiated with 10- to 12-day old juveniles
and lasted 4 weeks. The resulting nominal LAS concentrations were 125,
250, 500, 1000, 2500, and 4000 mg/kg sludge-soil mixture. Ten juvenile F.
candida were added to each of the 4 replicate vials per concentration
containing 30 g (wet weight) of the sludge-soil mixture. The numbers of
surviving adults and offspring were counted after 4 weeks.
Enchytraeus albidus
The enchytraeid worm reproduction test was initiated by introducing 10
worms with visible clitellum to each of 4 replicate vials per concentration.
Nominal LAS concentrations were 750, 1500, 2250, and 3000 mg/kg sludgesoil
mixture (dry weight). Test duration was six weeks. After 3 weeks, the
adult worms were removed and counted. At 6 weeks, the number of
offspring hatched from cocoons were counted.
Microbiological tests
The toxicity of LAS to microbiological processes was evaluated using one
aerobic system (simultaneous determination of aerobic respiration and
nitrification) and two anaerobic systems (denitrification and
methanogenesis). Nominal LAS concentrations were 0, 125, 250, 500, 1000,
and 2500 mg/kg mixture (dry weight) for both the aerobic and methanogenic
systems, and 0, 250, 500, 1500, 300, and 5000 mg/kg (dry weight) in the
dentrifying system.
GLP: Yes [ ] No [ ] ? [X]
Test Substance: The test substance for soil invertebrates consisted of an aqueous sodium salt
solution containing 14% (w/w) of 14 C-labeled C10-13 LAS (EniChem Augusta
Industriale; purity 95%). The average alkyl chain length of C10-13 LAS was
11.6 and the distribution was C10 14%, C11 34%, C12 32% and C13 20%. A
pure C12 LAS, 4-(2-dodecyl)benzene sulfonate sodium salt, was used in the
microbiological tests.
Remarks: Reproduction of E. albidus was the most sensitive endpoint (EC10 = 447
mg/kg dry weight). Danish laws stipulate a maximum cut-off value of 1300
mg/kg for LAS in sludge for agricultural use.
Reference: Gejlsbjerg, B., Klinge, C., Samsoe-Petersen, L., and Madsen, T. 2001.
Toxicity of linear alkylbenzene sulfonates and nonylphenol in sludgeamended
soil. Environmental Toxicology and Chemistry 20:2709-2716.
Reliability: 2 Valid with restrictions. Well documented publication, comparable to ISO.
4.6.2 TOXICITY TO TERRESTRIAL PLANTS
(a)
Species/Endpoints: See table
Results: The following table shows the available NOEC, EC10 and EC50 values for
twelve terrestrial plant species (in mg/kg dry weight).
Species Endpoint EC10 EC50
Brassica rapa Growth 134
Brassica rapa Growth 90 200
Malvia pusila Growth 204
Solanum nigrum Growth 169
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