Diammonium bis[carbonato-O]dihydroxyzirconate

Ecotoxicological Summary

Additional information

Aquatic

Information provided by the Sponsor indicated that at the pH and concentrations used in the ecotoxicity studies the test item was likely to have become unstable. It is considered likely that the addition of the test item to water resulted in the rapid decomposition of the substance to form zirconium hydroxide, together with accompanying release of carbonate and ammonium ions to the solution.

A standard acute toxicity study with the rainbow trout (Oncorhynchus mykiss) was conducted as a limit test at 100% v/v saturated solution and showed no effects. The 96-hour LC50 based on nominal test concentrations was greater than 100% v/v saturated solution of decomposition product(s). A standard acute toxicity study with Daphnia magna was conducted as a limit test at 100% v/v saturated solution and showed no effects. Therefore the 48 Hour EC50 was greater than 100% v/v saturated solution of decomposition product(s). Results from a standard chronic limit test study on Algae (Raphidoceles subcapitata), resulted in 72h EC50_growth> 100 mg/l.

In the absence of any effects on aquatic organisms (either lethal or sub-lethal) at the limit of solubility and not being technically feasible to determine the water solubility of AZC; the calculation of an aquatic PNEC value is considered inappropriate and unnecessary.

Sediment

No experimental data on sediment toxicity exist. The data are not required as the hazard assessment performed during the chemical safety assessment concludes that the substance is not classified and the risk assessment concludes that the compound is of no immediate concern to the environment. PNEC sediment calculation is considered inappropriate and unnecessary.

Terrestrial

No experimental data on terrestrial toxicity exist. The data are not required as the hazard assessment performed during the chemical safety assessment concludes that the substance is not classified and is of no immediate concern to the environment. In the combined repeat dose toxicity and reproduction/development screening no toxic effects on adult animals or reproductive and developmental effects on adults/off-spring were observed at the highest dose tested. This indicates that AZC poses no risk to predators or human via the food chain.

 

STP

No effects on sewage sludge were observed in a standard 3hr study on AZC. Hence the NOEC for AZC is 1000mg/l. No risk to sewage treatment plants is therefore envisaged.

 

In the absence of any ecotoxicological effect (either lethal or sublethal) in any organism the prediction of the PNEC values is considered to be both inappropriate and unnecessary.

 

Conclusion on classification

As the available data shows no toxic effects to the environment, the registered substance does not meet the criteria for classification as set out in 67/548/EEC and EC Regulation 1272/2008.