Choline hydrogen carbonate

Bioaccumulation: aquatic / sediment

Description of key information

RA_CAS 67-48-1_Calculation with BCFBAF v3.01 (EPIWIN software by US-EPA): 3.16 L/kg wet-wt, bioaccumulation is not expected.

Key value for chemical safety assessment

BCF (aquatic species):

3.16 L/kg ww

Additional information

A QSAR prediction of the Bioconcentration Factor (BCF) for Choline hydrogen carbonate is not possible. The substance is out of the domain of the EPIWIN software BCFBAF v3.01. Since the BCF is an important parameter, the result of the reliable read-across substance Choline chloride (CAS 67-48-1) is taken into account for the target substance. Details and justification of this procedure are described in the separate read-across statement written by Chemservice S.A. (2013).

The Bioconcentration Factor (BCF) of Choline chloride was determined the EPIWIN software BCFBAF v3.01 of US-EPA (Chemservice S.A., 2013). Furthermore, the whole body primary biotransformation rate estimation for fish was calculated with the notation that the bio half-life is normalized to 10 g fish at 15 °C. With this result 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) of the computer program BCFBAF from US-EPA a Bioconcentration Factor (BCF) of 3.16 L/kg wet-wt was calculated for Choline chloride. Using the Arnot-Gobas method, which is based on mechanistic first principles, an aquatic BCF of 0.893 L/kg wet-wt is the result.

The whole body primary biotransformation rate estimate for fish results in a half-life of 0.38 days, whereby the bio half-life is normalized to 10 g fish at 15 °C. The rate constant (kM) for 10 g fish is 125/day. This is taken into account to predict the apparent metabolism half-life in fish of Choline chloride. With the Arnot-Gobas method it is possible to differentiate between three trophic levels. For the lower trophic level the BCF results in 0.94 L/kg wet-wt, for a mid trophic level the result is 0.93 L/kg wet-wt and for the higher trophic level 0.89 L/kg wet-wt. As conclusion, bioaccumulation in aquatic organisms is not expected for Choline chloride and thus also not for the target substance Choline hydrogen carbonate.