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Environmental fate & pathways

Hydrolysis

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Reference
Endpoint:
hydrolysis
Data waiving:
study technically not feasible
Justification for data waiving:
other:

Description of key information

The test item as a whole was expected to be essentially insoluble in water. Therefore the test solution concentration required to dissolve all the components (less than half the water solubility) would be impractically low and a sufficiently sensitive analytical method was not available. The test item is a complex mixture, to which the test method is not ideally suited because each component that is unstable is likely to have its own hydrolytic rate. Hydrolysis products of components of a complex mixture can be the same as some of the already present components and differentiating these would not be possible. From information provided by the sponsor, the main functional groups within the components of the test item were alcohols, carboxylic acids and esters. Alcohols and carboxylic acids are generally stable to hydrolysis at environmentally relevant pH and temperature while esters are prone to hydrolysis, especially in alkaline conditions. However, the smaller ester-containing components may already be present in the test item and the larger esters may be significantly more hydrolytically stable due to low water solubility. Overall, these issues make hydrolysis testing unfeasible and testing was not carried out using Method 111 of the OECD Guidelines for Testing of Chemicals (13 April 2004) and Method C.7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Key value for chemical safety assessment

Additional information

Testing was not carried out using Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004 for the following reasons:

- The test item had a significant percentage of components that would have a water solubility too low to perform the test. Also, the test solution concentration would need to be less than half the water solubility. With such a wide range of components, and hence solubilities, the test solution would need to be at concentration that dissolves all components to be representative. This would be impractically low in order to perform the test without a sufficiently sensitive analytical method.

- The test item is a complex mixture which the test method is not ideally suited. This is because components that are unstable could have their own hydrolytic rate and a problem if some components are stable leading to conflicting results. Also, hydrolysis products of components of a complex mixture can be the same as some of the already present components and differentiating these would not be possible

Overall, these issues made the hydrolysis test unfeasible.

From information provided by the Sponsor, the main functional groups within the components of the test item were alcohols, carboxylic acids and esters. Alcohols and carboxylic acids are generally stable to hydrolysis at environmentally relevant pHs and temperatures while esters are prone to hydrolysis, especially in alkaline conditions. Although, with larger components having limited solubility the esters they may be significantly more hydrolytically stable. The smaller ester containing components could by hydrolytically unstable but their hydrolysis product may be present in the test item already with it containing a wide range of alcohols and carboxylic acids.