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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Description of key information

Calculation with BCFBAFWIN v3.00 (EPIWIN software by US-EPA), Bioconcentration factor (BCF): 3.16 (regression-based estimate) 

Key value for chemical safety assessment

BCF (aquatic species):
3.16 L/kg ww

Additional information

The prediction for the Bioconcentration factor (BCF) of the test substance was determined by the computer program BCFBAFWIN v3.00 (EPIWIN software) by US-EPA (Chemservice S.A., 2011). Furthermore the whole body primary biotransformation rate estimation for fish was calculated with the notation that the bio half-life normalized to 10 g fish at 15 °C. It is possible to predict the apparent metabolism half-life in fish for three different trophic levels (lower, mid and upper).

In general, the Bioconcentration factor of a substance describes the accumulation potential of a substance dissolved in water by an aquatic organism. BCFBAF v3.01 calculates also the BAF (Bioaccumulation factor) of the chemical, which is defined as the steady-state (equilibrium) ratio of the substance concentration in an organism to the concentration in the surrounding medium. However, this value is not taken into account for the risk assessment and is not relevant for a registration under REACH Regulation (EC) 1907/2006.

Using the regression-based estimate (traditional method) a BCF of 3.16 L/kg wet-wt was calculated. Using the Arnot-Gobas method, which is based on mechanistic first principles, the BCF results in a value of 0.90 L/kg wet-wt. The whole body primary biotransformation rate estimate for fish gives a half-life of 0.12 days, whereby the rate constant (kM) for 10 g fish is designated as 5.79/day. This is taken into account to predict the apparent metabolism half-life in fish for the substance. For the lower trophic level a BCF of 0.95 L/kg wet-wt is calculated, whereas for the mid trophic level the BCF will result in 0.94 L/kg wet-wt and the higher trophic level gives a value of 0.90 L/kg wet-wt.

This procedure is scientifically accepted and considered as reliable with restrictions (Klimisch 2). Furthermore, it can be taken into account for the chemical safety assessment.