Ethanol, 2,2'-iminobis-, N-C12-18-alkyl derivs.

Bioaccumulation: aquatic / sediment

Description of key information

The bioaccumulation potential for 2,2'-(C12-18 evennumbered alkyl imino) diethanol (CAS no 71786-60-2) is based on a measured log Kow of 0.7 (at pH 5 -6) using the slow-stirring method (OECD 123). With this log Kow a BCF is calculated of 3.162 L/kg ww assuming no metabolism.  The calculated BCF indicates a low bioaccumulation potential. 2,2'-(C12-18 evennumbered alkyl imino) diethanol is almost completely protonated under ambient conditions. In addition, the bioavailable fraction is completely degraded and a chronic exposure to a significant concentration is therefore unlikely. All primary fatty amine ethoxylates c12-18 are rapidly biotransformed by fish liver S9 fractions and  it is therefore unlikely that they will accumulate in the food chain.  

The predicted low bioaccumulation potential is supported by the low acute to chronic ratio observed in the long-term daphnia test.

The daphnia reproduction test result shows that at 1000 mg/L 100% of the parental daphnids were immobile within 5 days, while at the next lower test concentration of 320 µg/L there are only two immobile daphnia observed after 19 days and there is no detrimental effect on reproduction when compared to the control. These observations lead to the derivation of a NOEC of 320 µg/L resulting in a low acute-to-chronic ratio. A low acute-to-chronic ratio is indicative of a non-specific mode of action and is often associated with not systemic effects. This observation is consistent with the known effects of cationic surfactants on aquatic organisms, where toxicity is associated with physical binding to respiratory membranes. This explains the steep concentration curves seen and the lack of intermediate chronic effects on reproduction.

Key value for chemical safety assessment

BCF (aquatic species):

3.162 L/kg ww

Additional information

The bioaccumulation potential for 2,2'-(C12-18 evennumbered alkyl imino) diethanol (CAS no 71786-60-2) is based on a measured log Kow of 0.7 (at pH 5 -6) using the slow-stirring method (OECD 123). With this log Kow a BCF is calculated of 3.162 L/kg wwassuming no metabolism. The calculated BCF indicates a low bioaccumulation potential. 2,2'-(C12-18 evennumbered alkyl imino) diethanol is almost completely protonated under ambient conditions. In addition, the bioavailable fraction is completely degraded and a chronic exposure to a significant concentration is therefore unlikely. All primary fatty amine ethoxylates (C12 -18) were found to be rapidly biotransformed by fish liver S9 fractions and it is therefore unlikely that they will accumulate in the food chain.

The predicted low bioaccumulation potential is in addition supported by the low acute to chronic ratio observed in the long-term daphnia test. The daphnia reproduction test result shows that at 1000 mg/L 100% of the parental daphnids were immobile within 5 days, while at the next lower test concentration of 320 µg/L there are only two immobile daphnia observed after 19 days and there is no detrimental effect on reproduction when compared to the control. These observations lead to the derivation of a NOEC of 320 µg/L resulting in a low acute-to-chronic ratio. A low acute-to-chronic ratio is indicative of a non-specific mode of action and is often associated with not systemic effects. This observation is consistent with the known effects of cationic surfactants on aquatic organisms, where toxicity is associated with physical binding to respiratory membranes. This explains the steep concentration curves seen and the lack of intermediate chronic effects on reproduction.