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Ecotoxicological information

Sediment toxicity

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Description of key information

Study technically not feasible.

Key value for chemical safety assessment

Additional information

Substance is an extremely complex hydrocarbon UVCB. The substance is comprised of 21 different categories of components. The total number of individual components is estimated to be nearly 1000. It has been estimated that there are 210 possible isomers in the category of dialkyl benzenes alone. Standard tests for this endpoint are intended for single substances and are not appropriate for the risk assessment of this complex substance. Further complicating the sediment testing of Benzene, mono-C10-13-alkyl derivs., distn. residues is the extremely low water solubility (WATERNT estimates from 2.61e-03 to 5.83e-07 mg/L), extremely high log Kow’s (KOWWIN estimates from 7.87 to 19.62) and extremely high log Koc’s (KOCWIN estimates from 5.21 to 11.30 L/kg) of the individual components. These properties indicate that the Benzene, mono-C10-13-alkyl derivs., distn. residues components will be tightly bound to organic material in soil and sediments and will have little, if any, bioavailability. This lack of bioavailability can be observed in the results from the recent OECD 222 earthworm reproduction study conducted as a requirement for CoRAP. In the study, concentrations of Benzene, mono-C10-13-alkyl derivs., distn. residues of up to 1000 mg/kg (dry soil) had no effect on any of the measured endpoints (adult mortality, adult body weight, juvenile production). This resulted in NOECs of 1000 mg/kg (dry soil) and EC10s of >1000 mg/kg (dry soil).