Di-tert-butyl peroxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well-conducted GLP study performed according to established protocol. Test article is well characterized and a certificate of analysis is included in the report.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Di-tert-butyl peroxide

EC Number:

203-733-6

EC Name:

Di-tert-butyl peroxide

Cas Number:

110-05-4

Molecular formula:

C8H18O2

IUPAC Name:

2-(tert-butylperoxy)-2-methylpropane

Details on test material:

Di-tert-butyl peroxide, lot number 990-9801-124, was provided by Elf Atochem. The material is characterized as a colorless liquid; purity is given as 99.2.%.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Three animals were used as recommended by international guidelines. Animals were identified individually with a metal tag in the ear. On the day of treatment, the animals had a mean body weight of 2.4 +/- 0.1 kg. Animals were acclimated at least 5 days before the beginning of the study. Conditions in the animal room were as follows: temperature, 18 +/- 3 °C; relative humidity, 30 to 70%; light/dark cycle, 12 hr/12 hr; ventilations, approximately 12 cycles/hour of filtered, non-recycled air. Animals were housed individually in polystyrene cages. Each cage was equipped with a food container and a water bottle. During the study, the animals had free access to 112C pelleted diet. Drinking water filtered by a FG Millipore membrane (0.22 micron) was provided ad libitum.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Doses of 0.5 ml were placed on a 6 cm2 dry gauze pad, which was then applied to the right flank (application for 4 hours) or the left flank (application for 3 minutes) of the animals.

Duration of treatment / exposure:

Three minutes (one animal) or four hours (three animals).

Observation period:

One hour, 24, 48 and 72 hours after removal of the dressing or until reversibility of cutaneous reactions.

Number of animals:

Three

Details on study design:

The test substance was evaluated in one animal in a first assay. The duration of exposure was 3 minutes on one flank and 4 hours on the other flank. Since the test substance was not irritant in this first assay, it was then applied for 4 hours to two other animals in a second assay. The test substance was used undiluted. Doses of 0.5 ml were placed on a 6 cm2 dry gauze pad, which was then applied to the right flank (application for 4 hours) or the left flank (application for 3 minutes) of the animals. The test substance and the gauze pad were held in contact with the skin by means of an adhesive hypoallergenic aerated semi-occlusive dression and a restraining bandage. The untreated skin sered as control No residual test substance was observed on removal of the dressing.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48 h

Score:

0

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

72 h

Score:

1.7

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Irritant / corrosive response data:

After a 3-minute exposure (one animal), no cutaneous reactions were observed. After a 4-hour exposure (three animals), a very slight erythema (grade 1) was observed in one animal on day 1. A well-defined erythema (grade 2) was observed in the second animal between days 1 and 3, then a very slight erythema (grade 1) was noted on day 4. It was replaced by dryness ofthe skin from day 5 up to day 8. No cutaneous reactions were observed in the third animal.

Other effects:

None recorded.

Any other information on results incl. tables

Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.0 and 1.7 for erythema and 0.0, 0.0 and 0.0 for oedema.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under our experimental conditions, the test substance PEROXYDE DE DI-t-BUTYLE (batch No. 990-9801-124) is non-irritant when applied topically to rabbits.

Executive summary:

The potential of the test substance PEROXYDE DE DI-t-BUTYLE (batch No. 990-9801-124) to induce skin irritation was evaluated in rabbits according to OECD (No. 404, 17th July 1992) and EC (92/69/EEC, B.4, 31st July 1992) guidelines. After a 3 -minute exposure (one animal), no cutaneous reactions were observed. After a 4-hour exposure (three animals), a very slight erythema (grade 1) was observed in one animal on day 1. A well-defined erythema (grade 2) was observed in the second animal between days 1 and 3, then a very slight erythema (grade 1) was noted on day 4. It was replaced by dryness of the skin from day 5 up to day 8. No cutaneous reactions were observed in the third animal. Under our experimental conditions, the test substance PEROXYDE DE DI-t-BUTYLE (batch No. 990-9801-124) is non-irritant when applied topically to rabbits.