1-ethynylcyclohexanol

Endpoint summary

Description of key information

1-Ethynylcyclohexanol is an irritant to skin and mucous membranes.

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)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation

In a GLP-compliant OECD guideline 404 study (BASF AG, 1998), three New Zealand White rabbits were treated with 0.5 mL of undiluted 1-Ethinylcyclohexanol (= 1-Ethynylcyclohexanol) using semiocclusive conditions for 4 hours. An application site of 6.25 cm² was covered with the test substance. The animals were observed for 15 days and skin changes were recorded and scored according to Draize for every animal after 1, 24, 48, 72 hours, 8 and 15 days. The application of the test substance caused no edema and slight erythema of the skin. The erythema was not fully reversible within 15 days. In all animals, erythema extending beyond the area of exposure was observed during the observation period. The skin findings were reversible in one animal within 8 days after patch removal. In the two other animals the erythema persisted. Scaling as well as scaling extending beyond the area of exposure were observed after 8 and 15 days. Although the individual mean scores (24 to 72 h) for irritation did not warrant a classification, the test substance was deemed as irritating due to the fact that scaling was observed to the end of 15 days after application in two animals (nevertheless, in the study evaluation itself 1-Ethinylcyclohexanol was judged as a non-irritant compound). This study is classified as acceptable (key study).

In a primary skin irritation study (Smyth et al., 1962), five rabbits were exposed to 1-Ethinylcyclohexanol. The test substance was applied in a single dose of 0.01 mL to the clipped skin. After 24 hour exposure reactions were recorded in a 10-grade ordinal series (Grade 1 = no irritation, Grade 6 = necrosis [undiluted], Grade 10 = necrosis [0.01 % solution]). For 1-Ethinylcyclohexanol Grade 3 of max. 6 was noticed and it was deemed as a skin irritant. This study is classified as acceptable (supporting study).

 

Eye irritation

In an acute eye irritation/corrosion study (BASF AG, 1998), the right eyes of 3 New Zealand White rabbits were exposed by application of 100 µL undiluted 1-Ethinylcyclohexanol (= 1-Ethynylcyclohexanol) into the conjunctival sac of the right eyelid(s). The animals were observed after 1, 24, 48 and 72 hour(s) of treatment and 8 and 15 days afterwards. The eyes were washed out with tap water after 24 hours. Overall, the treatment caused very slight opacity and moderate conjunctivae/chemosis of the eye mucous membranes plus severe eye discharge within 24 hours and after 48 and 72 hours. Discharge of blood (3 animals) and suppuration (2 animals) was noticed up to 72 hours after application. The observed effects were fully reversible within 15 days. Due to the individual average scores (24 to 72 h) of conjunctivae and chemosis the test substance was graded as irritant under the conditions of this study. This GLP-compliant study satisfies the requirements of OECD test guideline 405 and is classified as acceptable (key study).

In an acute eye irritation/corrosion study (BASF AG, 1984), the right eyes of 3 Vienna White rabbits were exposed by application of 100 µL undiluted 1-Ethinylcyclohexanol (= 1-Ethynylcyclohexanol) into the conjunctival sac of the right eyelid(s). The animals were observed after 1, 24, 48, 72 hour(s) of treatment and 8 days afterwards. The eyes were not washed out. Overall, the treatment caused opacity and moderate-severe conjunctivae/chemosis of the eye mucous membranes within 1 hour and after 24, 48 and 72 hours. Discharge of blood and contracted pupil were noticed after application. The observed effects were not reversible within 8 days. Due to the individual average scores (24 to 72 h) and persistence of the irritation effects the test substance was graded as irritant under the conditions of this study. This study satisfies the requirements of OECD test guideline 405 in general and is classified as acceptable (supporting study).

An additional non-Guideline supporting study (Smyth et al., 1962) confirmed the eye irritating potency of 1-Ethynylcyclohexanol after instillation of 0.5 mL into the conjunctival sac of New Zealand White rabbits.

Respiratory irritation

There are no experimental results available for this endpoint.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

Based on the results for in vivo skin irritation, 1-Ethynylcyclohexanol is classified as Xi, R38 (irritating to skin) according to the criteria of EU Directive 67/548/EEC and as Cat. 2, H315 (causes skin irritation) according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No 1272/2008.

Based on the results of the in vivo eye irritation study, the test substance is classified as Xi, R36 (irritating to eyes) according to the criteria of EU Directive 67/548/EEC and as Cat. 2A, H319 (causes serious eye irritation) according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No 1272/2008.