Reaction products of sodium sulphide, sulphur, carbon disulphide and potassium hydroxide

Endpoint summary

Description of key information

There are no reliable data available on the aquatic toxicity of EC# 944-003-3 and reliable data cannot be obtained because the substance degrades rapidly at pH <11 to form highly volatile carbon disulphide (CS2). In a well documented study conducted according to DIN 38 412, DEV L15 and OECD principles for GLP, the acute toxicity (48-hr LC50) of EC# 944-003-3 to freshwater fish species Leuciscus idus (L.) was determined to be 55 mg/l. However, significant deficiencies in the study design exist. Specifically, there was no analytical monitoring and there was no consideration given to the degradation of the substance to carbon disulphide and losses of carbon disluphide due to volatilization. Sufficient data on CS2 do exist, however, and these data can be used to estimate the aquatic toxicity of EC# 944 -0033. In a static test with CS2 in a sealed system to determine the toxicity of CS2 to Daphnia magna, the 48-h EC50 for CS2 was 2.1 mg/l. The test fulfilled the requirements of OECD Guideline 202 but was not carried out in compliance with GLP. From these data, the toxicity of the substance being registered (EC# 944-003-3) is estimated to be 55 mg/l. The basis for this estimate is attached as background information in the supporting study for aquatic invertebrates (read-across to CS2). In addition, a test in sealed infusion bottles was carried out to determine the toxicity of CS2 to the alga Chlorella pyrenoidosa. The test was similar to the OECD Guideline 201, but was not carried out in compliance with GLP. The 96-h ErC50 for Chlorella pyrenoidosa was 21 mg/L. From these data, the toxicity of the substance being registered (EC# 944-003-3) is estimated to be 554 mg/l. The basis for this estimate is attached as background material in the supporting study for aquatic algae (read-across to CS2). From these data, coupled with the knowledge that CS2 is expected to be the only degradant produced at concentrations disproportionate to substances naturally present in the environment, and given that CS2 does not persist in the environment, it is reasonable to conclude that the substance being registered (EC# 944-003-3) does not meet current CLP criteria for classification as dangerous for the environment.

Additional information

There are no reliable data available on the aquatic toxicity of EC# 944-003-3 and relaible data cannot be obtained because the substance degrades rapidly at pH <11 to form highly volatile carbon disulphide (CS2). In a well documented study conducted according to DIN 38 412, DEV L15 and OECD principles for GLP, the acute toxicity (48-hr LC50) of EC# 944-003-3 to freshwater fish species Leuciscus idus (L.) was determined to be 55 mg/l. However, significant deficiencies in the study design exist. Specifically, there was no analytical monitoring and there was no consideration given to the degradation of the substance to carbon disulphide and losses of carbon disluphide due to volatilization. Sufficient data on CS2 do exist, however, and these data can be used to estimate the aquatic toxicity of EC# 944 -0033. In a static test with CS2 in a sealed system to determine the toxicity of CS2 to Daphnia magna, the 48-h EC50 for CS2 was 2.1 mg/l. The test fulfilled the requirements of OECD Guideline 202 but was not carried out in compliance with GLP. From these data, the toxicity of the substance being registered (EC# 944-003-3) is estimated to be 55 mg/l. The basis for this estimate is attached as background information in the supporting study for aquatic invertebrates (read-across to CS2). In addition, a test in sealed infusion bottles was carried out to determine the toxicity of CS2 to the alga Chlorella pyrenoidosa. The test was similar to the OECD Guideline 201, but was not carried out in compliance with GLP. The 96-h ErC50 for Chlorella pyrenoidosa was 21 mg/L. From these data, the toxicity of the substance being registered (EC# 944-003-3) is estimated to be 554 mg/l. The basis for this estimate is attached as background material in the supporting study for aquatic algae (read-across to CS2).From these data, coupled with the knowledge that CS2 is expected to be the only degradant produced at concentrations disproportionate to substances naturally present in the environment, and given that CS2 does not persist in the environment, it is reasonable to conclude that the substance being registered (EC# 944-003-3) does not meet current CLP criteria for classification as dangerous for the environment.