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Environmental fate & pathways

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The bioaccumulation potential of a series of LAS homologues and isomers were evaluated in flow-through studies with fathead minnows. The BCFs were 87 L/kg for a standard mixture typical of LAS in European detergent formulations (average alkyl chain length = C11.6) and 22 L/kg for a representative environmental sample (filtered Mississippi river water, average alkyl chain length = C10.8).

In a supporting study, the bioconcentration of LAS in the marine shrimp Palaemonetes varians was measured in a radiotracer study.The BCF55 for shrimp was calculated to be 159 L/kg. A DT50 of 14 hrs was calculated, and only 1% of the body burden of the test substance remained in the shrimp after 8 days.

Additional information

The bioaccumulation potential of LAS has been evaluated and found to be low based on aquatic data in fish. BCF values ranged from between 2 and < 1000 L/kg, with a BCF value of 99 for the 2-phenyl isomer of the C12 homologue. In vitro study demonstrate that low bioaccumulation is due to rapid biotransformation. BCF values for mixtures can be calculated based on the weight fraction of each homologue. The calculated BCF was 87 L/kg for a standard mixture typical of LAS in European detergent formulations (average alkyl chain length = 11.6). The calculated BCF value was 22 L/kg for a representative environmental sample (filtered Mississippi river water, average alkyl chain length = C10.8), demonstrating that BCF is decreased by environmental processes such as biodegradation and absorption, which reduce aquatic concentrations.