Transformation/dissolution characterization of tungsten and tungsten compounds for aquatic hazard classification.

The transformation/dissolution protocol (T/DP) for metals and sparingly soluble metal compounds was applied to determine the transformation/dissolution (T/D) characteristics of yellow tungsten trioxide, WO ; blue tungsten oxide, WOx, x taken as 2.9; tungsten disulphide, WS ; tungsten metal, W; 3 samples of tungsten carbide, WC; sodium tungstate, Na WO · 2H O; ammonium paratungstate (APT), (NH ) (H W O ) · 4H O; and ammonium metatungstate (AMT) (NH ) (H W O ) · 3H O. The T/D data were used to derive aquatic hazard classification outcomes under the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS) and European Union Classification, Labelling and Packaging of Substances and Mixtures (EU CLP) schemes by comparing the data with selected acute and chronic ecotoxicity reference values (ERVs) of 31 and 3.