4-methylpentan-2-ol

Endpoint summary

Description of key information

In standard primary irritation studies in rabbits, MIBC is was irritating to skin and the eyes. Human volunteers exposed to MIBC vapors at 50 ppm experienced eye irritation in most subjects with nose and throat irritation experienced at higher concentrations.  The maximum tolerable concentration was considered to be 25 ppm.  

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:

adverse effect observed (irritating)

Additional information

Skin irritation:

 

A skin irritation study on methyl iso butyl carbinol has been performed in accordance with OECD Guidelines for the Testing of Chemicals No. 404 and in compliance with GLP (Parcell, 1998).  In this study, 3 New Zealand White rabbits were exposed to 0.5 mL of undiluted methyl iso butyl carbinol on the clipped dorsal lumbar region under semi-occlusive conditions.  Animals were exposed to the test compound for 4 hours and observations were recorded at 1, 24, 48, and 72 hours after removal of the patch and residual test substance.  Additional daily observations were made up to a maximum of 14 days.  Skin reactions were scored according to a prescribed numerical system.  In all 3 animals, well-defined erythema with slight edema was observed. In addition, desquamation of the stratum corneum, characterized by dryness and sloughing of the skin, developed in all animals. In one rabbit, thickening of the skin was observed. Dermal responses were fully resolved by either Day 10 or 12 in 2 animals. However, very slight erythema was still observed in one animal at Day 14. No signs of toxicity or ill health were observed in any rabbit during the observational period. The individual mean scores over 24, 48 and 72 hours were 2.0, 2.0 and 2.0 for erythema and 2.0, 1.0 and 1.7 for edema.

 

Eye Irritation:

 

An eye irritation study on methyl iso butyl carbinol has been performed in accordance with OECD Guidelines for the Testing of Chemicals No. 405 and in compliance with GLP (Parcell, 1998).  In this study, 0.1 mL of undiluted methyl iso butyl carbinol was instilled into one conjunctival sac of each of 3 New Zealand White rabbits.  Ocular changes were assessed 1, 4.5, 24, 48, 72 hours after treatment, and additional daily observations were made up to a maximum of 14 days.  Eye irritation reactions were observed and scored according to guideline methods.  No clinical signs of systemic toxicity or ill health were observed in any rabbit during the course of the study.  Corneal opacification (Grade 1 or 2), iridial inflammation (Grade 1), and a diffuse beefy red or crimson coloration of the conjunctivae and swelling with eyelids about half-closed were observed in all animals. These effects were resolved within 7 or 14 days after instillation. Under the conditions of this study, methyl iso butyl carbinol induced corneal opacification, iridial inflammation, and conjunctival irritation. Individual mean scores over 24, 48 and 72 hours were 1.0, 0.7 and 2.0 for corneal opacity, 0.7, 0.7 and 0.3 for iritis, 2.3, 1.3 and 1.3 for conjunctival redness and 1.0, 0.3 and 0.3 for chemosis.

 

Respiratory tract irritation

A study with human volunteers (12/sex) indicated that vapor exposure to MIBC at 50 ppm for 15 minutes resulted in eye irritation in most subjects with nose and throat irritation experienced at higher concentrations. The maximum tolerable concentration was considered to be 25 ppm (Silverman et al., 1946).

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Effects on respiratory irritation: irritating

Justification for classification or non-classification

Regulation (EC) No 1272/2008

- Annex VI Table 3.1

Classification		Labelling
Hazard Class and Category Code(s)	Hazard Statement Code(s)	Pictogram Signal Word Code(s)	Hazard Statement Code(s)	Suppl. Hazard statement code(s)
STOT SE 3	H335	GHS07	H335

- Annex VI Table 3.2

Classification	Risk phrases	Indication(s) of danger
Xi; R37	37	Xi

Self-classification

-Regulation (EC) No 1272/2008

Classification		Labelling
Hazard Class and Category Code(s)	Hazard Statement Code(s)	Pictogram Signal Word Code(s)	Hazard Statement Code(s)	Suppl. Hazard statement code(s)
Eye Irrit. 2 STOT SE 3	H319 H335	GHS07	H319 H335

- Directive 67/548/EEC

Classification	Risk phrases	Indication(s) of danger
Xi; R36/37/38	36/37/38	Xi