Methyl chloroacetate

Endpoint summary

Description of key information

Skin irritation: read across: ethyl chloroacetate (OECD 404). 
Eye irritation: Experimental results on methyl chloroacetate: no guideline was followed. However, the test method was similar to OECD 405.

Additional information

Based on the results observed in the skin irritation study, strong damages of the skin in the form of redness, swelling, scabbing, cracking, hardening, sheds and burns were observed. Under the test conditions described, the substance proved to have a strong skin irritant and corrosive effect. However, the duration of exposure was 24 hours instead of 4 hours as recommended in the guidelines. The study is considered to be not reliable. There is a skin irritation study conducted on the analogue ethyl chloroacetate which has been conducted according to the recommended guideline OECD 404. Based on the results obtained in this study, the substance is classified as skin irritating.

The analogue ethyl chloroacetate which shares the same functional group with methyl chloroacetate, also has comparable values for the relevant molecular properties. These properties are:

- a low log Pow value which is 0.94 -1.12 for ethyl chloroacetate and 0.63 for methyl chloroacetate,

- a high water solubility which is 20 g/l at approximately 20 ºC for ethyl chloroacetate and 51.6 g/l for methyl chloroacetate and

- similar molecular weights which are 122.55 for ethyl chloroacetate and 108.52 for methyl chloroacetate.

Furthermore, in the acute dermal toxicity studies conducted with methyl chloroacetate with rats and rabbits, no indication of necrosis is reported in the study although erythema and oedema were observed in the animals. Finally, the substance methyl chloroacetate is included in the list of harmonised classifications and labellings and it is classified as "Skin irritant Category 2".

Based on the results observed in an acute inhalation study, methyl monochloroacetate was found to be a pronounced irritant of the respiratory tract at levels of 250 -1000 ppm.

Based on the results observed in the eye irritation study, the mean scores for 24-72 h for eye irritation are 2.22, 2.17 and 2.22 for cornea opacity, conjunctiva redness and conjunctiva chemosis, respectively. However, there is no information on the reversibility of the observed damage. In this context, persistent lesions are considered those which are not fully reversible within an observation period of normally 21 days. Substances are also classified in Category 1 if they fulfil the criteria of corneal opacity ≥ 3 or iritis > 1,5 detected in a Draize eye test with rabbits, recognising that such severe lesions usually do not reverse within a 21-day observation period. In this study, at 72 hours, three animals showed corneal opacity = 3. Although there is no information on the reversibility of the damage, the substance is included in the list of harmonised classifications and labelling and it is classified as "Irreversible effects on the eyes Category 1".

Effect level: empty Endpoint conclusion: Adverse effect observed

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

Based on the results observed in the skin irritation study conducted with the analogue ethyl chloroacetate, the results observed in the acute dermal toxicity studies conducted with the substance methyl chloroacetate and the harmonised classification included in the CLP Regulation, the substance is classified as "Skin irritant Category 2".

Based on the results observed in an acute inhalation study, methyl monochloroacetate was found to be a pronounced irritant of the respiratory tract at levels of 250 -1000 ppm. Therefore, the substance is classified as STOT SE Category 3, H335: May cause respiratory irritation.

Based on the results observed in the eye irritation study, the mean scores for 24-72 h for eye irritation are 2.22, 2.17 and 2.22 for cornea opacity, conjunctiva redness and conjunctiva chemosis, respectively. However, there is no information on the reversibility of the observed damage. Based on the harmonised classification included in the CLP Regulation, the substance is classified as "Irreversible effects on the eyes Category 1".