2-methylpropan-2-ol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 hour exposure followed by 72 hour observation period

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted according to generally accepted methods for a dermal irritation study.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Principles of method if other than guideline:

No information on guideline used, if any, in this study. Tertiary butyl alcohol (0.5 mL) was applied to each of 2 intact and 2 abraded skin sites in 3 male and 3 female New Zealand White rabbits for 24 hours. No information on type of coverage, i.e. occluded versus non-occluded, used. Application was followed by a 72 hour observation period. Erythema and edema were scored at 24 hours and 72 hours using the Draize scoring system.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpropan-2-ol

EC Number:

200-889-7

EC Name:

2-methylpropan-2-ol

Cas Number:

75-65-0

Molecular formula:

C4H10O

IUPAC Name:

2-methylpropan-2-ol

Constituent 2

Reference substance name:

tertiary butyl alcohol

IUPAC Name:

tertiary butyl alcohol

Details on test material:

-Identity (according to report): t-butyl alcohol - 99.9%
-Purity: 99.9% per sponsor

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS:
-Source: Kuiper’s Rabbit Ranch, Gary Indiana
-Animals: 3/sex
-Age: young adults
-Quarantine period: 7 days
-Weight at Study Initiation: 2593-2798 grams
-Housing: individual hanging wire-mesh cages
-Diet: Purina® Certified Rabbit Chow® # 5322
-Identification method: ear tag
-Method of Animal Distribution: computer-generated table of pseudo-random numbers

ENVIRONMENTAL CONDITIONS: no information

IN-LIFE DATES:
-Date of study initiation: 15 April 1981
-Date of study termination: 18 April 1981

Test system

Type of coverage:

not specified

Preparation of test site:

other: Two intact and two abraded sites per rabbit

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5 mL/site; 2.0 mL/rabbit

Duration of treatment / exposure:

24 hr

Observation period:

24 hours and 72 hours after exposure

Number of animals:

3/sex

Details on study design:

TEST SITE:
-Area of exposure: 4 sites per animal, 2 abraded and 2 intact

SCORING SYSTEM:
-Draize scoring system

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 72 hours

Score:

0.4

Reversibility:

fully reversible within: 72 hours

Remarks on result:

other: Skin irritation score is based on the average of all the erythema scores plus the average of all the edema scores.

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 hours

Score:

0.7

Max. score:

2

Reversibility:

fully reversible within: 72 hours

Remarks on result:

other: Average erythema score for intact or abraded skin was 0.7 at 24 hr and 0 at 72 hr. Well-defined erythema was seen in 1 male for intact and abraded skin. All other values were scored as 0 to 1.5 (slight, not well-defined).

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 hours and 72 hours

Score:

0

Remarks on result:

other: The average edema group score for intact and abraded skin was 0.0 at 24 hours and 72 hours.

Irritant / corrosive response data:

There was no edema noted in any of the animals during the observation period. Well-defined erythema was limited to intact and abraded skin in one male rabbit. Responses ranged from none to slight in all remaining animals for both intact and abraded application. All animals were normal by the 72 hour observation period.

Other effects:

No other abnormalities were noted during the observation period.

Applicant's summary and conclusion

Interpretation of results:

slightly irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

Tertiary butyl alcohol is not classified as a primary skin irritant. Minimal erythema and no edema were observed when the test material was applied to both intact and abraded rabbit skin for twenty-four hours. All effects were fully reversible by the 72-hour observation.

Based on a total absence of edema, a mean erythema score of 0.7 at 24 hours, and full reversibility of erythema by 72 hours following application of tertiary butyl alcohol to intact and abraded rabbit skin for 24 hours, tertiary butyl alcohol is not classifiable for Skin Irritation/Corrosion according to GHS.

Executive summary:

In a primary dermal irritation study, young adult New Zealand white rabbits (3 males, 3 females) were dermally exposed to 2 mL of tertiary butyl alcohol for 24 hours.  Test material (0.5 mL) was applied to each of 2 intact and 2 abraded sites for each rabbit.  Animals were then observed for 72 hours.  Irritation was scored by the method of Draize.  No edema was noted.  The test material caused minimal erythema at 24 hours in some rabbits but no signs of erythema or edema were present at the 72 hour observation period.  Tertiary butyl alcohol is not considered a dermal irritant in this study.