Potassium O-pentyl dithiocarbonate

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

potassium O-pentyl dithiocarbonate

Type of composition:

boundary composition of the substance

State / form:

solid: bulk

> 90 - < 95 % (w/w)

Reference substance:

potassium O-pentyl dithiocarbonate

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference 2

Name:

potassium O-pentyl dithiocarbonate

Type of composition:

legal entity composition of the substance

State / form:

solid: bulk

Related composition:

potassium O-pentyl dithiocarbonate

> 90 - < 95 % (w/w)

Reference substance:

potassium O-pentyl dithiocarbonate

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

Reference substance:

potassium O-pentyl dithiocarbonate

This impurity is considered relevant for the classification and labelling of the substance

PBT status:

the substance is not PBT / vPvB

Justification:

When water is added to Potassium amyl xanthate it reacts with water to form the others substances: alcohol, potassium carbonate, trithiocarbonate and carbon disulphide because of its high water solubility.

Hydrolysis will be a significant factor in determining the environmental fate of Potassium amyl xanthate. In neutral or mildly alkaline solutions, Potassium amyl xanthate decomposes to the alcohol, carbon disulphide, potassium carbonate and potassium trithiocarbonate, the two salts arising from neutralisation of carbon disulphide with the potassium hydroxide liberated. In more strongly alkaline media, hydrogen sulphide is liberated. However, strongly alkaline conditions are unlikely to be encountered under the conditions of use in the mining industry. The half-life at pH 7 at 25°C is reportedly about 260 hours, increasing to over 500 hours in the pH range 8 to 11.

Potassium amyl xanthate is hydrolytically unstable when exposed to acidic conditions, reverting rapidly to ethanol, carbon disulphide and potassium hydroxide, and therefore will not persist in the acidic environment of tailings dams. If discharged to waterways, the chemical would be likely to persist for at least some days, hydrolysing only slowly in this more neutral environment. However, it is not expected to bioaccumulate in view of its ionic character

Potassium amyl xanthate does not fulfil the criteria for persistency, bioaccumulation and toxicity as laid down in the TGD (EC, 2003). Therefore, this substance is not consideredon PBT or vPvBsubstance.