Isononyl alcohol

Endpoint summary

Description of key information

Irritating to skin. Based on test data for the material.
Potential to cause serious eye damage. Based on test data for the material.

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

Skin

Three skin irritation studies in rabbits have been undertaken.

In the key study, Isononanol (0.5 ml) was applied to the shaved skin of three rabbits under semi-occluded dressings for 4 hours. Dermal reactions were assessed using the Draize method 1, 24, 48 and 72 hours after removal of the dressings, and on Days 6, 8,10 and 14. The mean score for erythema at 24, 48 and 72 hours was 2.67 for each animal, and for oedema 2.67 for two animals and 3.0 for the third. The skin was dry, cracked and hardened, with scab formation, sloughing and new skin, amongst the three animals, during Days 8 to 14. In a second skin irritation study in rabbits using 24 -hour occluded exposure, Isononanol was similarly found to be irritant to intact skin.

In a third, supporting study, rabbits were subjected to a 4-hour exposure to isononanol via a semi-occlusive dermal application.  Dermal reactions were scored for erythema and edema according to the method of Draize at 45 minutes, 24, 48, and 72 hours and 7 days post patch removal.  All animals exhibited some signs of erythema and edema within 48 hours post patch removal.  Except for one animal, all signs of dermal irritation were resolved within 7 days.  The mean skin irritation scores between 24 and 72 hours were: erythema 1.83 and edema 0.22. 

The key study was conducted to OECD acute irritation test guidelines, although not to GLP.

Eye

Three eye irritation studies in rabbits have been undertaken.

In the key study, Isononanol (0.1 ml) was instilled into the right eye of three rabbits. Responses to treatment were assessed using the Draize method 1, 24, 48 and 72 hrs after instillation and again on Days 6, 8, 10, 14, 17 and 21. Easily discernible areas of corneal opacity, reddening of the iris and diffuse beefy-red and slight or obvious swelling of the conjunctivae were observed amonst all animals. Corneal opacity and reddening of the iris persisted in one animal on Day 21. In a second eye irritation study with Isononanol, instilled into one eye of six rabbits, comparable irritation and persistance were observed.

In a third, supporting study, 6 rabbits had their left eye instilled with 0.1 ml of isononanol and were evaluated for signs of eye irritation at 1, 24, 48 and 72 hours and 7 days post exposure according to the method of Draize.  Slight signs of irritation were noted within 1 hour post exposure, but these effects were resolved by the seven day observation point.  Mean eye irritation scores between 24 and 72 hours were: cornea score 0.83, iris score 0.63, and conjunctival redness 1.42. 

The key study was undertaken to OECD acute irritation test guidelines, although not to GLP.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: highly irritating

Justification for classification or non-classification

In one of the two skin irritation studies, the mean scores for erythema and oedema for all three animals exceeded the classification threshold for irritancy, and in one of the two eye irritation studies, one animal had changes to the cornea and iris that persisted to Day 21.

Isononanol is therefore classified as irritant to skin and has the potential to cause serious eye damage, according to the general classification and labeling requirements for dangerous substances and preparations (Directive 67-548-EEC) and the classification, labeling and packaging (CLP) regulation (EC) No 1272/2008