LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
Results
The single-species chronic toxicity data summarized by van de Plassche et al. (1999) resulted in a
calculated HC5 value of 0.32 mg/L. This value is based on a fit of the data to a log-normal
distribution. Using the goodness-of-fit comparisons as described above, the best fit with the van de
Plassche et al. data was found with the log-logistic distribution (Versteeg et al. 1999). A HC5 value
of 0.36 mg/L was determined for C11.6 LAS with the log-logistic distribution. The data used
(“Original VdP Values”), the cumulative probability distribution of the data and the HC5 calculation
are shown below.
These same methods were also applied to the available chronic data provided in the dossier and
summarized in Table 12A of this SIAR. Using the log-logistic distribution of the normalized
NOEC data, the HC5 value calculated is 0.24 mg/L. The data used (“Available Chronic Values”),
the cumulative probability distribution of the data and the HC5 calculation are shown below.
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