Sodium O-isobutyl dithiocarbonate

Toxicity to other aquatic organisms

Description of key information

Expert Judgement 
Xanthates are used in the mining industry as flotation agents in the recovery of metal sulphides. The amount of xanthate used is very small relative to the quantity of ore treated, being approximately 250 to 350 g/tonne of ore.
During use, the solid sodium isobutyl xanthate is mixed with water to form a dilute aqueous solution and typically concentrations in the order of 10% are used. The pH of the solution ranges from 7 to 11.
The flotation process is fully automated. The process takes place in open tanks and there is the potential for formation of carbon disulphide vapour. However, the concentration of Sodium isobutyl xanthate in the flotation tank is low and, therefore, the release of carbon disulphide would be expected to be low. Air monitoring data, although limited and of poor quality, indicate that the atmospheric levels of carbon disulphide are below 10 ppm in the flotation areas. The risk to workers during the flotation process is considered to be low.
Due to the absence of chemical groups or other structural alerts this substance is not considered to exhibit an high hazard potential.
The results suggest for sodium O-isobutyl dithiocarbonate that direct and indirect exposure of  other aquatic organisms is unlikely.
Therefore testing for Toxicity to other aquatic organisms does not need to be performed. 

Additional information

Expert Judgement

Xanthates are used in the mining industry as flotation agents in the recovery of metal sulphides. The amount of xanthate used is very small relative to the quantity of ore treated, being approximately 250 to 350 g/tonne of ore.

During use, the solid sodium isobutyl xanthate is mixed with water to form a dilute aqueous solution and typically concentrations in the order of 10% are used. The pH of the solution ranges from 7 to 11.

The flotation process is fully automated. The process takes place in open tanks and there is the potential for formation of carbon disulphide vapour. However, the concentration of Sodium isobutyl xanthate in the flotation tank is low and, therefore, the release of carbon disulphide would be expected to be low. Air monitoring data, although limited and of poor quality, indicate that the atmospheric levels of carbon disulphide are below 10 ppm in the flotation areas. The risk to workers during the flotation process is considered to be low. Due to the absence of chemical groups or other structural alerts this substance is not considered to exhibit an high hazard potential.

The results suggest for sodium O-isobutyl dithiocarbonate that direct and indirect exposure of other aquatic organisms is unlikely. Therefore testing for Toxicity to other aquatic organisms does not need to be performed.