Chromium iron oxide

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is highly insoluble in water

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
According to Annex VIII, Column 2 of Regulation (EC) 1907/2006, " The study does not need to be conducted if: - the substance is highly insoluble in water".

According to ECHA guidance on IR & CSA, Chapter R.7b, Table R.7.9-1, hydrolysis refers to the “Decomposition or degradation of a substance by reaction with water” as a function of pH and only applies to organic substances. Hydrolysis is a specific form of solvolysis which generally describes “a reaction with a solvent, a lyonium ion or lyate ion, involving the rupture of one or more bonds in the reacting solute” as well as the heterolytic cleavage of the solvent. “More specifically the term is used for substitution, elimination and fragmentation reactions in which a solvent species is the nucleophile ("alcoholysis" if the solvent is an alcohol, etc.)” (Muller – IUPAC recommendations, 1994, Pure & Appl Chem 66/5: 1077-1184). Chromium iron oxide is an inorganic pigment that does not dissolve to any relevant extent under regular environmental conditions. Hence, hydrolysis as defined by IUPAC (1994) is not possible. Furthermore, inorganic substances such as chromium iron oxide cannot degrade or decompose but can be transformed e.g. by oxidation, reduction, speciation, precipitation. Thus, experimental data or other adequate and reliable information about the rate of hydrolysis, the extent of hydrolysis or the rate and extent of hydrolysis in different environments of chromium iron oxide cannot be generated.