Nanomaterials can release into the aquatic environment from emerging consumer nanoproducts. Nanoscale silver (nAg) is the most nanomaterial used in consumer products. In the present study acute aquatic toxicity of a colloidal form of silver nanoparticles, which is one of the most productive nanomaterials in Iran, was investigated in two fish, an amphibian and a crustacean species in accordance with OECD guidelines for the testing of chemicals. According to the results, the 96h median lethal concentrations (LC50) of mentioned colloid to larval Rainbow trout (Oncorhynchus mykiss) and juvenile Zebra fish (Danio rerio) were 0.71±0.16 and 0.014±0.001 mg/L respectively; Also the 48h LC50 of this chemical to the marsh frog tadpoles (Rana ridibunda) was 0.055±0.004 mg/L; In addition the 48h median effective concentration (EC50) of this material to the water flea neonates (Daphnia magna) was 0.002 mg/L. According to the present results, this colloidal silver nanoparticles should be classified according to EEC (European Economic Community) as “very toxic” and also according to GHS (Globally Harmonized System) of classification and labeling of chemicals as “category acute 1” to tested aquatic organisms. Since colloidal silver nanoparticles can be dangerous to aquatic organisms, inhibiting the accidental or intentional entrance of colloidal nanosilver into the aquatic ecosystems should be carefully considered. New methods also are needed to develop for preventing release of nAg from consumer products as well as treatment of the wastewater containing nanomaterials before entering to the environment.
