2-methylbutane

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991-03-05 to 1991-03-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable with restrictions because while there is no statement regarding whether this study was conducted according to GLP or equivalent, the study protocol was provided.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Study type:

study with volunteers

Endpoint addressed:

skin irritation / corrosion

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Protocol supplied by testing laboratory. The objective was to evaluate the test material for its potential to cause irritation after a single 24-hour semi-occlusive patch application.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methylbutane

EC Number:

201-142-8

EC Name:

2-methylbutane

Cas Number:

78-78-4

Molecular formula:

C5H12

IUPAC Name:

2-methylbutane

Details on test material:

- Name of test material (as cited in study report): 2-methylbutane
- Substance type: C5 aliphatic
- Physical state: unknown
- Test substance characteristics and analysis: responsibility of the sponsor: Exxon Biomedical Sciences, New Jersey

Method

Type of population:

general

Subjects:

- Number of subjects exposed: 30
- Sex: 28 female, 2 male
- Age: 18 - >60
- Known diseases: no skin/dermatological conditions that would interfere with the study results

Ethical approval:

confirmed and informed consent free of coercion received

Route of exposure:

dermal

Reason of exposure:

intentional

Exposure assessment:

not specified

Details on exposure:

Each subject received one application of the test material under semi-occlusive conditions. The sample was applied to the outer surface of the upper arm, to the Webril pad of the Professional Medical, Inc. patch. The test materials remained in contact with the skin for 24 hours, unless irritation was noted. 30 minutes after patch removal, the test sites were scored, and were scored again 24 hours after patch removal. Test subjects remained under observation for a maximum of 4 hours after exposure.

Examinations:

The patches remained on for 24 hours unless irritation was noted, and after removal, the test site was gentrly rinsed with water and gently patted dry with a paper towel. Sites were graded approximately 30 minutes after patch removal, and again 24 hours after the initial patch removal. A scale from 0 to 7 was used to score the reactions to the test material.

Medical treatment:

If the test material elicited severe reactions, the patches were removed and the test site gently rinsed with water and patted dry with paper towel.

Results and discussion

Clinical signs:

No clinical observations were noted, and no adverse reactions were observed during exposure.

Results of examinations:

Overall irritation score: 0.33
This was calculated as the mean of all scores from both time periods (0.5 hours and 24 hours after exposure).
No individual data was provided for this test material.
No data on reversibility was collected.

Any other information on results incl. tables

The results of the study indicate that 2 -methylbutane was clinically non-irritating.

Applicant's summary and conclusion

Conclusions:

The average dermal irritation score for this test material was 0.33 on a scale from 0 to 7. 2 -Methylbutane was considered non-irritating.

Executive summary:

In a dermal irritation study, 30 human volunteers were dermally exposed to n-pentane for 24 hours, via a semi-occlusive patch. Thirty minutes after patch removal, the test sites were scored, and were scored again 24 hours after patch removal. Test subjects remained under observation for a maximum of 4 hours after exposure. If the test material elicited severe reactions, the patches were removed.

The average dermal irritation score for this test material was 0.33 on a scale from 0 to 7. 2 -Methylbutane was considered non-irritating. This study was given a reliability rating of 2, reliable with restrictions, because while there is no statement regarding whether this study was conducted according to GLP or equivalent, the study protocol was provided.