tert-pentyl hydroperoxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

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)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

tert-pentyl hydroperoxide

EC Number:

222-321-7

EC Name:

tert-pentyl hydroperoxide

Cas Number:

3425-61-4

Molecular formula:

C5H12O2

IUPAC Name:

2-methylbutane-2-peroxol

Test material form:

other: liquid

Details on test material:

. description: colourless liquid
. container: one plastic flask
. date of receipt: 7 April 1998
. storage conditions: at room temperature and protected from light
. expiry date: September 1998.
. The pH of the test substance, measured at CIT, was approximately 3.
. Purity : 87.6 %, in water

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Animals:
Breeder: Elevage Cunicole de Val de Selle, 80160 Prouzel, France.
Number and identification: one animal was used. The animal was identified with a metal tag in the ear.
Weight: on the day of treatment, the animal had a body weight of 2.4 kg.
Acclimatization: at least 5 days before the beginning of the study.

Environmental conditions:
The animal was housed in a polystyrene cage (35 cm x 55 cm x 32 cm or 48.2 cm x 58 cm x 36.5 cm) equipped with a food container and a water bottle
. temperature: 18 ± 3°C
. relative humidity: 30 to 70%
. light/dark cycle: 12 h/12 h
. ventilation: approximately 12 cycles/hour of filtered, non-recycled air.
. Food and water were provided at libitum

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5 ml

Duration of treatment / exposure:

3 minutes and 4 hours

Observation period:

The skin was examined approximately 1 hour, 24, 48 and 72 hours after removal of the dressing, and then daily until day 9.

Number of animals:

1

Details on study design:

Doses of 0.5 ml of the test substance 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 animal.
As possible irritant effects were anticipated, 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.
The animal was killed on day 9 for ethical reasons.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: mean erythema score after a 3-min exposure

Basis:

animal #1

Time point:

other: 24 h, 48 h, 72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 9 days

Remarks on result:

other: Black coloration and thickening of the skin from day 5.

Results 2

Irritation parameter:

other: mean oedema score after a 3-min exposure

Basis:

animal #1

Time point:

other: 24, 48 and 72 hours

Score:

2

Max. score:

4

Reversibility:

other: score masked by thickening of the skin from D5

Results 3

Irritation parameter:

other: mean erythema scores after a 4 hour-exposure

Basis:

animal #1

Time point:

other: 24h, 48 h and 72 h

Score:

4

Max. score:

4

Reversibility:

not reversible

Remarks:

9 days (the animal was sacrified at day 9 for ethical reasons)

Remarks on result:

other: necrosis until day 9, then tissue destruction

Results 4

Irritation parameter:

other: mean oedema scores after a 4 hour-exposure

Basis:

animal #1

Time point:

other: 24 h, 48 h, 72 h

Score:

4

Max. score:

4

Reversibility:

not reversible

Remarks:

scoring masked by necrosis from D5

Irritant / corrosive response data:

After a 3-minute exposure: A well-defined or moderate erythema (grade 2 or 3) was observed between day 1 and day 5 and
a slight oedema (grade 2) was noted between day 1 and day 4. A thickening and a black colouration of the skin were noted from day 5.

After a 4-hour exposure: A severe erythema (grade 4) and a slight or severe oedema (grade 2 or 4) were observed from day 1. Signs of necrosis were observed from day 2; they have masked the evaluation of cutaneous reactions from day 5. A tissular destruction was recorded on day 9.

Other effects:

No other effects.
The animal was killed on day 9 for ethical reasons.

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

Under the experimental conditions, tert-amyl hydroperoxide is corrosive when applied topically to rabbits for 4 hours.

Executive summary:

The potential of the test substance LUPEROX TAH 85 to induce skin irritation was evaluated in rabbits according to OECD guideline no. 404 and GLP. The test substance was applied for periods of 3 minutes and 4 hours to one male New Zealand White rabbit. A single dose of 0.5 ml of the undiluted test substance was applied to the closely-clipped skin of each flank. The test substance was held in contact with the skin by means of a semi-occlusive dressing. Cutaneous reactions were observed approximately 1 hour, 24, 48 and 72 hours after removal of the dressing and then daily until day 9. The mean values of the scores for erythema and oedema were calculated.

After a 3-minute exposure, a well-defined or moderate erythema was observed between day 1 and day 5 and a slight oedema was noted between day 1 and day 4. A thickening and a black colouration of the skin were noted from day 5. After a 4-hour exposure, a severe erythema and a slight or severe oedema were observed from day 1. Signs of necrosis were observed from day 2; they have masked the evaluation of cutaneous reactions from day 5. A tissular destruction was recorded on day 9.

The animal was killed on day 9 for ethical reasons. LUPEROX TAH 85 is corrosive when applied topically to rabbits for 4 hours.