Registration Dossier

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

Determination of adsorption coefficient was not carried out using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001, as the test item was considered to be not applicable to the method and that any result produced would likely be inaccurate. For purposes of risk assessment, the absorption coefficient value was estimated using available data and EUSES version 2.1.2.

Key value for chemical safety assessment

Koc at 20 °C:
3 880

Additional information

Determination of adsorption coefficient was not carried out using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001, as the test item was considered to be not applicable to the method and that any result produced would likely be inaccurate. Some of the components in the test item contain an amine functional group. These amines would be ionised throughout the environmentally relevant pH range forming cations, which could be subjected to cationic exchange with soils. This mode of adsorption can be significantly stronger than that of adsorption to the organic content of the soil. As the HPLC method does not take into consideration the effect of cationic exchange, the results can be underestimated. Additionally, amines undergo secondary interactions with silica based HPLC columns due to the silanol groups and this also can add to the uncertainty of the result. The HPLC estimation method is generally consider not applicable to highly surface active substances such as the registered substance. For example, surface active substances can form micelles in an aqueous environment but these would not form in the same way in the organic solvent environment of the test. Overall it was considered that the HPLC method would lead to significant uncertainty in any result generated and for that reason the test was not performed.