LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Endpoint: Mortality [X]; Reproduction rate [ ]; Other [X] mobility and feeding
responses
Exposure period: 6 weeks
Results: For adult survival: NOEC = 0.2 mg/L, LOEC = 0.4 mg/L
For reproduction: NOEC < 0.2 mg/L, LOEC = 0.2 mg/L
Analytical monitoring: Yes [X] No [ ] ? [ ]
Method: Two 6-week chronic studies were performed in which an amphipod, a
pulmonate snail, and an operculate snail were tested together. A serial
diluter was used to provide continuous flow conditions into duplicate 4gallon
glass aquaria for each of five concentrations plus controls. Ten snails
were placed in each of two replicate chambers per concentration. Complete
immobilization was taken as a sign of death for the amphipods. Mean
measured LAS concentrations were 0.2, 0.4, 1.0, 1.9, and 4.4 mg/L. Only
adult amphipods were started in each 6-week test. Following the termination
of the second 6-week test, however, the newly hatched Gammarus were
counted and allowed to remain in each respective test chamber for 15 weeks
of additional exposure.
GLP: Yes [ ] No [X] ? [ ]
Test substance: Commercial LAS formulation containing 14% LAS, 2.3% alcohol ethoxylate
oxide condensate, 2.5% sodium soap, 48% sodium tripolyphosphate, 9.7%
sodium silicate, 15.4% sodium sulphate, and 8.1% moisture and
miscellaneous.
Remarks: Adult survival was affected at all concentrations after 6-weeks in a somewhat
dose-responsive manner, as shown in the following table. Based on adult
survival, the NOEC is 0.2 mg/L and the LOEC is 0.4 mg/L.
Mean LAS
Concentration
(mg/L)
4.4
1.9
1.0
0.4
0.2
Control
Duplicate
Chambers
A
B
A
B
A
B
A
B
A
B
A
B
Trial 1 Trial 2
0
0
10
10
40
30
30
40
70
40
80
70
0
0
0
0
20
30
20
40
50
50
60
40
Newly hatched amphipods were not produced in the highest concentration
(4.4 mg/L). The results on survival of F1 Gammarus from the second 6-week
study, and the final numbers of gravid F1 females and F2 young produced
after 15 weeks of exposure are shown below. Control F1 females were the
first to release F2 young, and this occurred after 9 weeks. Females began
liberation of F2 young at 13 and 13.5 weeks for the 0.2 and 0.4 mg/L
chambers, respectively. Based on variability and apparent reproductive
effects at the lowest concetration, no NOEC value could be determined. The
LOEC is 0.2 mg/L.
UNEP PUBLICATIONS 215