Potassium methanolate

Endpoint summary

Description of key information

Data waiving due to skin corrosive properties of the substance according to ANNEX VII-VIII, column 2 of the REACH regulation.
    
    
    
    
    
    
    
    
    
    

according to ANNEX VII, column 2 of the REACH regulatio




















 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There are no data available on the acute toxicity of potassium methanolate. Studies on acute toxicity do generally not need to be conducted according to Annex VII-VIII, Section 8.5, Column 2 of the REACH regulation as potassium methanolate is classified as corrosive to the skin.

However, the available data on the acute toxicity of the hydrolysis products potassium hydroxide (CAS No. 1310-58-3) and methanol (CAS No. 67-56-1) were taken into account for classification and labelling purposes.

 

According to the OECD SIDS for potassium hydroxide, acute oral toxicity values between 273 and 1230 mg/kg body weight were reported (OECD, 2002), with the relevant LD50 values for classification of 333 – 388 mg/kg bw. Neither acute inhalation nor dermal toxicity studies have been located for potassium hydroxide. Please refer to the endpoint summary of potassium hydroxide for more details.

 

With respect to the acute toxicity of the hydrolysis product methanol, it is discussed in the OECD SIDS for sodium and potassium methanolate (OECD, 2006) that:

-       with regard to the possibility of methanol toxicity in humans through oral uptake of potassium methanolate, it should be considered that methanol doses that would lead to deaths in humans (300 to 1000 mg methanol/kg bw) correspond to potassium methanolate doses between 657 to 2190 mg/kg bw. Such dose levels would already cause considerable irritation of the mucous membranes in the oral cavity, pharynx and gastrointestinal tract and humans are unlikely to be exposed orally to such dose levels.

-       it is very unlikely that through inhalation exposure to potassium methanolate air concentrations could be reached that would be in the range of causing methanol toxicity. The tolerable exposure will be limited by the highly corrosive properties of the substance.

-       it is very unlikely that dermal exposure of humans to potassium methanolate would lead to an uptake of methanol that would be sufficiently high to cause acute methanol toxicity.

 

Based on the fact, that the acute toxicity of potassium methanolate is mediated by its alkalinity and studies on acute toxicity are unnecessary for corrosive substances, the data on acute toxicity of methanol are not included in the dossier.

 

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).

OECD SIDS Initial Assessment Report for SIAM 13 (2002): Potassium Hydroxide (CAS No: 1310-58-3).

OECD SIDS Initial Assessment Report for SIAM 19 (2004): Methanol (CAS No: 67-56-1).

Justification for classification or non-classification

There are no data available on the acute toxicity of potassium methanolate. Studies on acute toxicity do generally not need to be conducted according to Annex VII-VII, Section 8.5, Column 2 of the REACH regulation as potassium methanolate is classified as corrosive to the skin. For classification and labelling purposes, the available data of the hydrolysis products (potassium hydroxide (CAS No. 1310-58-3) and methanol (CAS No. 67-56-1) were taken into account. Due to the corrosive potential of potassium methanolate, it is unlikely that methanol contributes much to the acute toxicity. Taken into account the available LD50 values and the harmonised classification for potassium hydroxide according to CLP Regulation No 1272/2008, Annex VI Table 3.1 (Acute Toxicity Cat. 4 (minimal classification), H302), potassium methanolate is also regarded as harmful if swallowed and thus, fulfils the CLP / UN-GHS criteria for classification:

 

CLP / UN-GHS: Acute toxicity - oral, Category 4 (H302)

 

There are no data available for the dermal or the inhalation route, but as potassium methanolate is classified as corrosive to skin and eyes, no further data is needed. Taken into account the data on corrosivity additional labelling with EUH071 - Corrosive to the respiratory tract is justified according to CLP Regulation No 1272/2008.