LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Table 15. Results of Model Ecosystem Studies 1
Type of
Ecosystem
Experimental
Stream
Experimental
Stream
Avg.
Alkyl
Chain
Length
Exposure
Duration
Most Sensitive Endpoint
(Species)
C12 56 days Increased drift, reduced
benthic abundance
(Invertebrates)
C11.9 45 days No effects observed
(Periphyton, detritus,
invertebrates, snails,
amphipods and fish)
Outdoor Ponds C12 56 days Reduced egg production
(Cyclopedia)
Aquaria with
sediment and
activated sludge
effluent
Aquaria with
sediment and
activated sludge
effluent
NOEC
(mg/L)
Reference (Reliability)
0.27 Belanger et al. 2002,
dossier 4.7a (1)
>0.36 Fairchild et al. 1993,
dossier 4.7f (2)
3.5 Huber 1989; Huber et al.
1987, dossier 4.7 g (2)
C11.9 28 days Microbial function 0.5 Larson and Maki 1982,
dossier 4.7h (2)
C11.9 28 days Growth (Bluegill sunfish) 1.0 Maki 1981, dossier 4.7i
(2)
In Situ River C11.9 21 days Photosynthesis inhibition
(phytoplankton)
Bottles filled with
lake water
C11.8
C13.3
3 hours/
month for 6
months
1 Reliability of Studies = (2) or (1)
* EC50 values
4.2 Terrestrial Effects
Photosynthesis inhibition
(phytoplankton)
9.8 Lewis et al. 1993,
dossier 4.7j (2)
3.4*
1.9*
Lewis and Hamm 1986,
dossier 4.7k (2)
A large amount of ecotoxicity data are available for terrestrial organisms (e.g., Carlsen et al. 2002).
Many of the studies, both laboratory and field, have been conducted recently in Denmark on soil
organisms including plants, soil invertebrates, and microorganisms (Jensen and Krogh 1999; Jensen
et al. 2001; Holmstrup and Krogh 2001; Elsgaard et al. 2001a,b; Brandt et al., 2003).
Terrestrial Toxicity – Soil Invertebrates
The data from studies evaluating the effects of LAS on soil dwelling organisms have recently been
summarized in Jensen et al. (2001). However, the reliability of the individual studies could not be
directly assessed so they are not included in Table 16. Additional information is available from
other investigations of LAS toxicity on terrestrial invertebrates with test durations ranging from 14
days to 6 weeks (Holmstrup and Krogh 2001; Mieure et al. 1990). These additional data are
summarized in Table 16. All studies used natural agricultural soil, with the exception of Mieure et
al. (1990), who used artificial soil. In all studies, C11.5/C11.6 LAS was added as aqueous solutions
and not associated with sludge, which would be the normal route of exposure for agricultural soil.
The bioavailability of LAS is greatly affected by interaction with sludge (Elsgaard et al. 2001a, b)
and the toxicity in Table 16 below may or may not reflect exposure to free LAS in soil interstitial
water. It is not known whether the data appropriately account for bioavailability in sludge-amended
soils. (See Dossier section 4.6.1 for more information.)
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