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water solubility
Data waiving:
other justification
Justification for data waiving:
Justification for type of information:
The test item is a complex substance for which only a part of the composition has been clearly identified due to technical issues. The application of the standards Water solubility determination methods is limited due to technical issues and limited knowledge of composition of the test item.
(1) Considering the nature of the known constituents, we anticipate that the composition of the solubilised fraction should be different from the initial composition and that this composition should vary with the loading rate. However due to analytical issues, the composition of the substance (as such or in water) cannot be deeply determined and due to the large part of the unknown composition, we cannot anticipate the behavior of the constituents of the mixture in water.
(2) TOC determination was conducted in previous ecotox studies on similar test items. However, some technical problems have been encountered using TOC analyzer (pollution of the measuring chamber apparently due to the test samples composition / insoluble fraction of complex natural substances, in spite of prefiltration). Therefore a COD analysis was conducted in ecotox studies on the test item instead of a TOC determination (althought TOC analysis is more sensitive). Unfortunately, the COD analysis does not allow to estimate the concentration of the substance solubilised in water and then the water solubility of the substance.
(3) Determining the water solubility of some « target » peaks detectable by chromatography may be considered. However the water solubility obtained of these « target » peaks would lead to partial results without proof that the toxicity is linked to the target « peaks ». Considering the very complex nature of the test item, the information obtained from testing is considered as not relevant or of practical use for subsequent assessments and therefore conducting the test is waived based on Chapter R.7a: Endpoint specific guidance-Version v6.0, July 2017, R., which reports : “for complex substances the information obtained from such testing is not relevant or of practical use, and therefore conducting the test may be waived where the data is irrelevant for subsequent assessments ».

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion