Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The log Kow is a useful screening tool for many substances, and it is generally assumed that non-ionised organic substances with a log Kow below 3 (4, GHS) are not significantly bioaccumulative(ECHA, 2008).

In accordance with current ECHA guidance (2008), several current models were used for a screening to estimate a BCF (Bioaccumulation factor) for SymWhite® 377 using Kow as input parameters. None of the used models predicted BCFs > 1200 L/Kg ww. In addition, the models most applicable to the considered substance predicted BCF values in the range of 12.3 – 59.1L/kg ww well below the PBT or vPvB criteria according to Annex XIII of REACH regulation (i.e., BCF > 2000 L/kg, > 5000 L/kg, respectively).

The bioaccumulation potential is one of the criteria used for the PBT/vPvB assessment. A provisional assessment can be made against screening criteria based on the Kow for substances that are expected to accumulate via passive diffusion such as SymWhite® 377. Furthermore, no specific uptake mechanism apart from lipophilic partitioning is known or suspected. Structure and physico-chemical properties of SymWhite® 377 (i.e. vapour pressure, water solubility, Kow, molecular weight, and pKa). According to ECHA “Guidance on information requirements and chemical safety assessment / Part C: PBT assessment” (May 2008), the criteria for bioaccumulation (B and vB) are not fulfilled, if the logPow is ≤ 4.5.

For organic substances with a log Kow value below 4.5 it is assumed that the affinity for the lipids of an organism is insufficient to exceed the B criterion, i.e. a BCF value of 2000 L/kg ww.

Furthermore, there is no convincing evidence that SymWhite® 377 can biomagnify in the food chain (BMF < 1). Therefore, the criteria for “bioaccumulating” and for “very bioaccumulating” are not fulfilled.