Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

One experimental study was performed on the major isomer of the transformation product (further to metabolic activity, in this case a biodegradation study) of the registered substance (96% C6 isomer), by the Institute of Ecotoxicology in Japan in 2013. This study was performed in the context of the notification of the registered substance in Japan in 2014, under the New Chemical Substances Control Law. This study followed the latest OECD 305 Guideline (2012) and was conducted using the C6 isomer of the transformation product dissolved in water at two sub-lethal concentrations for a period of 28 days. The authors considered that steady state was reached on day 28 although there was evidence that steady-state may have already occurred by day 7 of the study. In both concentrations extremely low BCFs were determined (11-25 with a mean of 15 at the highest water concentration of approximately 0.07 mg/L based on the major isomer and <21 -<35 [LOD] at the lowest water concentration of approximately 0.007 mg/L based on the major isomer). Results from the second isomer were almost identical. This study conclusively demonstrated that the major breakdown product of the registered substance will not bioaccumulate to any significant degree in aquatic organisms.

This result was supported by QSAR predictions.

The bioconcentration factors (BCF) of the registered substance and its transformation product (C6 and C7 isomers) were evaluated with BCFBAF model v3.01 from EPI Suite v4.1, which fulfilled all OECD principles. These substances are within the domain of the BCFBAF model based on the molecular weights and fragments present in the BCFBAF database.

For C6 and C7 isomers of the registered substance (parent), the BCFs were estimated to be 382 L/kg whole body weight and 435 L/kg whole body weight, respectively.

For C6 and C7 isomers of the transformation product, the BCFs were estimated to be 374 L/kg whole body weight and 490 L/kg whole body weight, respectively. As the QSAR estimate for the C6 isomer of the transformation product is higher than the experimental value, the QSARs can considered to be a conservative estimate of the BCF for the registered substance and its degradation products.

Additional information