Registration Dossier

Categories

Categories

Category name:
Iron (II & III) salts category

Justifications and discussions

Category definition:
The Iron (II & III) salts category comprises five soluble coagulant iron salts (ferric and ferrous chloride and ferrous and ferric sulphate and ferric chloride sulphate, including their various hydrated forms).
Category order description:
The Iron (II & III) salts category members can not be placed in a meaningful order.
Category rationale:
The Category hypothesis is that the iron salts category comprises a directly analogous group of Iron III and II (ferric and ferrous) salts, with counterions which are ubiquitous and do not require additional consideration. The formation of a Category is justified, on the basis of a self-consistent model of the behaviour and properties of these substances. All of these salts will dissociate immediately in aqueous media under normal environmental conditions of pH, ambient temperature and dissolved oxygen, to the respective anions and kations, and then be subject to further change of oxidation and speciation state according to the conditions. The composition of this equilibrium depends on these conditions rather than the ferric or ferrous character of the original iron salt as the kations transform readily.
With regard to the physicochemical and toxicological property data sets the parent category members were not equal but due to the transformation equilibrium of the iron species a common view is considered meaningful. Thus these endpoints were included in the category in order to facilitate read across where applicable. Nonetheless the discussion and assessment of iron (II) and (III) are not identical.