(+)-menthol

Endpoint summary

Description of key information

D-Menthol is :
Skin irritant.
Slightly eye irritant

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Ocular irritation

The ocular irritation potential of D-menthol at 50% and 100% according to the current OECD-guideline 405 was assessed. All examinations were performed  in the same institute according to the same protocol; the means of Draize scores were recorded after 24, 48, and 72 h. The vehicle diethylphthalate (DEP) alone used in these tests didn’t shown any irritating properties in the opposite eye of the  animals. In all studies with the test compounds only slight reactions of cornea and conjunctiva were observed, depending on the concentration tested. There was no reaction in the iris observed in all cases. Moreover, after treatment with menthol liquid (at 50 and 100%) slight redness of conjuctival was seen on day 3 in 2/4 animals. This adverse effect recovered completely within 7 days.

Then, a 50% diethylphtalate solution of D-menthol caused slight conjunctival irritation to the rabbit eye.

Skin irritation

In a primary dermal irritation study (four SFP albino female rabbits), were dermally exposed to 0.5ml of 5 different concentrations of D-menthol in DiEthyl Phthalate (DEP) (i.e. HR 89/620005 - 100%, 50%, 25%, 5% and 1%) for 4 hours according to OECD 404 guideline. The test was performed in the same institute and following the same protocol than L-menthol.

Very slight erythema (barely perceptible) was observed up to 25%, whereas at higher concentration and undiluted, moderate to severe erythema is recorded (such was almost the case with L-menthol).

D-menthol (HR 89/620005, 100%) was examined for its skin irritating potential in a valid study conducted according to OECD test guideline n°404 and under GLP. D-menthol was a dermal irritant at 100% and at 50%. However, 25% diethylphthalate solution shall not be classified as skin irritant.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: slightly irritating

Justification for classification or non-classification

Skin irritation: The substance D-menthol at 100% meets the criteria for classification and labelling for this endpoint, as set out in Regulation (EC) No. 1272/2008. Based on a valid key study performed according to OECD 404 protocol, the substance showed irritating properties with a maximum draize score of 3 that were reversible although not fully reversed at the highest concentration of 100% but the underlying skin remained intact. At concentrations of 50% and below, the test data did not meet the criteria for classification as skin irritant.

Eye irritation: according to CLP classification criteria, the substance does not meet the criteria for classification and labelling for this endpoint since all scores were below the limits specified for eye irritation Category 2 as set out in Regulation (EC) No. 1272/2008.