Gold

Endpoint summary

Additional information

In a GLP, guideline transformation/dissolution full test, performed at loading rates of 1, 10 and 100 mg/L and pH 6, gold showed no dissolution above the Limit of Detection of 0.3 µg/L (Brouwers, 2012). The standard approach for assessing the toxicity of a poorly soluble metal would be to compare the amount of dissolution determined in a transformation/dissolution test with the acute and chronic ecotoxicity reference values for a soluble salt of the metal in order to assess the toxicity impact of the test item in aqueous medium. However, the quantities of gold which are released into solution from gold metal during a transformation/dissolution test are diminishingly small (<0.3 µg/L) and it is unlikely to be possible to determine the speciation of any dissolved metal. On this basis the ecotoxicity endpoints for gold metal are waived.