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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Steady state estimates of the BCF was considered to be the most accurate of the available BCF estimates from investigation of an analogue substance (US EPA OPPTS 850.1730 and OECD 305).

Additional information

A bioconcentration study in rainbow trout was conducted according US EPA OPPTS 850.1730 and OECD 305 Guidelines using an analogue substance.

Supply of test water: Continuous flow-through diluter system The length of exposure was 97 days with 35 days uptake and 62 days depuration.

The target concentrations were solvent control, 0.25 ug/L and 2.5 ug/L. The mean measured concentrations were <LOQ, 0.25 ug/L and 2.8 ug/L for the solvent control, low exposure level, and high exposure level respectively.

Based on the mean measured concentrations in water the Steady state BCF for the whole fish at the low exposure level was 426 (266-619 95% CI) and the steady state BCF for the whole fish in the high exposure level was 432 (210-571 95% CI).

Steady-state concentrations of 14C-test material were achieved in the tissues of rainbow trout (Oncorhynchus mykiss) after 31 days. The mean measured water concentrations based on total radioactivity were 0.25 and 2.8 μg/L. Steady-state BCF values for the 0.25 μg/L test concentration, based on total radioactivity test material concentrations were 301, 625 and 436 in edible, non-edible and whole fish tissue, respectively. Steady-state BCF values for the 2.8 μg/L test concentration, based on total radioactivity test material concentrations were 260, 673 and 432 in edible, non-edible and whole fish tissue, respectively. Test material depurated slowly from fish tissue and consequently the study was terminated after reaching 62 days depuration, even though concentrations in the fish tissues remained above 10% of the steady state values. Because the declining concentrations in the tissues did not follow the first order assumptions kinetics required for valid kinetic estimates of BCF, the results of the derived kinetic BCF values were questionable and the steady state estimates of the BCF was considered to be the most accurate of the available BCF estimates from this study.