Potassium methanolate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

No information is available on the mutagenicity of potassium methanolate. Taken into account the available in vitro data on genotoxicity of the hydrolysis products methanol and potassium hydroxide, there were some ambiguous or positive results observed in different in vitro genotoxicity tests with methanol, which were further evaluated in vivo. However, the most of the available in vitro studies with methanol were negative. For potassium hydroxide there is no evidence for a mutagenic potential.

Endpoint conclusion

Endpoint conclusion:

no study available

Genetic toxicity in vivo

Description of key information

No in vivo data are available for potassium methanolate and its hysrolysis product potassium hydroxide. The weight of evidence of all available data for the hydrolysis product methanol suggests that methanol is unlikely to have any relevant mutagenic activity.

 

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No information is available on the mutagenicity of potassium methanolate. The abiotic hydrolysis of potassium methanolate either in aqueous culture media of in vitro test systems or with tissue water results in the formation of methanol (CAS No.67-56-1) and potassium hydroxide (CAS No. 1310-58-3). The latter dissociate into the corresponding cations (K⁺) and anions (OH^-). Therefore, data of the hydrolysis products were taken into account for the hazard assessment of potassium methanolate (please refer to the endpoint summaries of potassium hydroxide and methanol for details).

 

Conclusion:

 

No data on mutagenicity of potassium methanolate are available. For potassium hydroxide, there is no evidence of mutagenic potential. Further testing on the in vitro genotoxicity of potassium hydroxide is considered scientifically unjustified due to the dominating effect of high pH. Testing at non-physiological pH might give false-positive responses, which means that the effect is of a methodical kind and not valid to assess the genotoxicity under realistic conditions. For methanol, the weight of evidence suggests that the substance is unlikely to have any relevant mutagenic activity. For further details please refer to the endpoint summaries of methanol and potassium hydroxide.

Therefore, it can be concluded that there is no concern with regard to the mutagenic activity of potassium methanolate. This is also supported by available data of the structurally related sodium methanolate (CAS No. 124-41-4). Like potassium methanolate, sodium methanolate reacts violently with tissue water. This results in the formation of similar hydrolysis products, methanol and sodium hydroxide. The latter dissociates into the corresponding cations (Na⁺) and anions (OH^-). Due to the structural similarities of potassium and sodium methanolate, they both were assessed together by OECD (2006). For sodium methanolate, one negative Ames assay with a limited number of strains is available. Like for potassium hydroxide, there is also no evidence for a mutagenic potential of sodium hydroxide (OECD, 2006).

 

References not included in IUCLID:

OECD SIDS Initial Assessment Report for SIAM 22 (2006): Category of Methanolates: Sodium Methanolate, Potassium Methanolate (CAS No: Sodium Methanolate: 124-41-4; Potassium Methanolate: 865-33-8).

Justification for classification or non-classification

The available information on the genotoxic potential of potassium methanolate and its hydrolysis products methanol and potassium hydorxide is conclusive but not sufficient for classification according to CLP (1272/2008/EC) / UN-GHS.

.