4-hydroxy-2,2,6,6-tetramethylpiperidine-1-ethanol

Endpoint summary

Description of key information

The test item caused minimal skin irritation effects below the threshold of significance in rabbits. After instillation into the eye of rabbits, clear ocular irritation was observed in all animals.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not 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 an acute dermal irritation study following OECD guideline 404 and in compliance with GLP, three rabbits were exposed to 0.5g of the test substance for 4 hours. The test substance was applied unchanged to the shaved right flank of each animal. A control gauze patch was applied to the contralateral flank. Both patches were moistened before application with 0.5 % (w/v) carboxymethylcellulose in 0.1 % (w/v) aqueous polysorbate 80. Observations were made 1, 24, 48, 72 hours and 7 days after removal of the gauze patches. Slight erythema and slight edema were observed already at the 1 hour time point. The mean values of the recordings 24 to 72 hours after application are 0.6 erythema and 0.1 for edema. All effects were below the threshold of significance and reversible within 72 hours the latest. Therefore, the test item is regarded as not irritating to the rabbit skin under the conditions employed (Ciba-Geigy, 1992). A supporting study confirmed these findings (Stillmeadow, 1994)

Eye irritation

In an acute eye irritation/corrosion study according to OECD guideline 405 and in compliance with GLP, 0.1 ml of the undiluted test item was instilled into one eye of each of three male New Zealand White rabbits. Observations were made 1, 24, 48, 72 hours and 7, 10 and 14 days after instillation. The substance caused reversible irritation of the iris, cornea and conjunctivae. The average scores (24 -72 hours) for each animal were 0.67, 0 and 2.0 for cornea, 0.67, 0.67 and 1.0 for iris, 2.67, 3.0 and 3.0 for redness and 1.0, 1.0 and 1.0 for chemosis, respectively. In addition, the mucosa of the conjunctival sac appeared strongly damaged at the readings 24, 48, and 72 hours (two animals) or only at the readings 48 and 72 hours (one animal) after instillation of the test article. In one animal a slight vascularisation of the lower marginal part of the cornea was observed from day 7 until day 10. The reactions were reversible within 10 (one animal) and 14 days (two animals) after instillation of the test article. Based on the results of this study, the test article is considered irritating to the rabbit skin (Ciba-Geigy, 1992).

Justification for selection of skin irritation / corrosion endpoint:
GLP-compliant guideline study

Justification for selection of eye irritation endpoint:
GLP-compliant guideline study

Effects on eye irritation: irritating

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008 (CLP). As a result the substance is considered to be not irritating to the skin but requires classification with Eye Irritation Cat 2A under Regulation (EC) No 1272/2008, as amended for the sixth time in Regulation (EC) No 605/2014.