Registration Dossier

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

BCF: 20

Key value for chemical safety assessment

BCF (aquatic species):
20 dimensionless

Additional information

A GLP study according to the OECD Guideline 305 was performed to assess the bioaccumulation of Y-15099 (Yakata, 2003). The carp Cyprinus carpio was exposed to the test substance in concentrations of 0.25 (Level 2) and 2.5 mg/L (Level 1) for 60 days. In contrast to the OECD Guideline, the depuration of the substance after the uptake was not evaluated. A steady-state was reached after approx. 32 days indicating a slow uptake of the substance. Based on the results at steady-state the BCF was calculated to be 20 at a test concentration of 2.5 mg/L. The BCF could not be calculated at Level 2 concentration of 0.25 mg/L since the test item in all test fish at the last three successive analysis was not more that minimum determination limit of the test item. However, because all BCFs were less than 100, it was evaluated that a steady-state was reached within 60th day. Chemical analysis of the test item in test water showed that the test species were continuously exposed to the desired concentrations. The results of this study indicate that there is a low potential for Y-15099 to bioaccumulate in animal tissues as indicated by the very low BCF determined for fish.

Since the substance Y-15099 is hydrolytically unstable, the hydrolysis products also need to be taken into account for the assessment. They were already assessed in this bioaccumulation study. The low bioaccumulation potential for the hydrolysis products ethanol and silanetriol, (3-mercaptopropyl)- is supported by a log Kow < 3. The third hydrolysis product octanoic acid with a log Kow of 3.05 (Hansch et al., 1995) might has a low potential to bioaccumulate, but a supporting QSAR calculation resulted in a BCF of 83.64 L/kg wet weight indicating a low potential for bioaccumulation (Müller, 2012).

References: Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants.,: American Chemical Society., 1995.