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Environmental fate & pathways

Adsorption / desorption

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Reference
Endpoint:
adsorption / desorption: screening
Data waiving:
study technically not feasible
Justification for data waiving:
other:

Description of key information

Key value for chemical safety assessment

Additional information

An experimental study according to OECD 121 is technically not feasible. It was proved in experimental studies on physico-chemical parameters (e.g. partition coefficient) that HPLC combined with UV or RI detection is not suitable for the determination of the test substance. The compound could not be detected and possibly did not elute from the analytical column. Thus, no experimental study could be performed. Since the substance is an organometallic compound (Q)SAR models are not suitable to be used as well.
However, the substance is expected to hydrolyze quickly in contact with water. Thus, the assessment of the hydrolysis products rather than the parent substance was considered to be relevant. The expected hydrolysis products are dioctyltin dichloride (DOTC), ethanol, acetic acid and silicium dioxide. From research activities it is known that organotin compounds have an affinity to bind to organic matter (e.g. sewage sludge) by adsorption (RPA, 2005; Fent, 2013). For the expected main hydrolysis product (DOTC) a log Koc of 5.47 is reported. Ethanol and acetic acid are not expected to adsorb to organic matter based on their low log Kow values (< 3; see IUCLID section 4.7).
Thus, adsorption of the organotin moiety of the substance to organic matter cannot be excluded.

References

Fent, K. (2013): Ökotoxikologie. 4th Edition, Thieme.

RPA (2005): Risk assessment studies on targeted application of certain organotin compounds. Final report prepared for the European Commission.