Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

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Additional information

A bioaccumulation in fish study is available for one of the streams in this category, with the highest BCF for edible portions of Salmo gairdneri being 25.9. Walsh et al (1977) conducted a 56 day flow through test, with analytical confirmation of exposure concentrations, to determine the bioaccumulation of xylene. As there was no significant difference in the concentrations measured in the edible portions of the fish after 1 or 56 days exposure, nor at the different exposure concentrations, we conclude that the bioaccumulation is initially rapid but the subsequent amounts bioaccumulated do not increase with exposure duration.

The screening criterion for bioaccumulation in the PBT assessment is that a substance with a log Kow of ≤4.5 is not B or vB. Experimental data for the xylene isomers and ethylbenzene (log Kow of 3.12-3.2) indicate that this criterion is met. In addition, a measured BCF is available for mixed xylenes, with the highest reported value for fish being 25.9 L/kg. Therefore, based on the definitive criteria for bioaccumulation, the streams are not considered bioaccumulative (B) or very bioaccumulative (vB).