Di-tert-butyl sec-butylidene diperoxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study conducted in 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Di-tert-butyl sec-butylidene diperoxide

EC Number:

218-507-2

EC Name:

Di-tert-butyl sec-butylidene diperoxide

Cas Number:

2167-23-9

Molecular formula:

C12H26O4

IUPAC Name:

2,2-bis(tert-butylperoxy)butane

additive 1

Reference substance name:

Hydrocarbons, C4, 1,3-butadiene-free, polymd., triisobutylene fraction, hydrogenated

EC Number:

297-629-8

EC Name:

Hydrocarbons, C4, 1,3-butadiene-free, polymd., triisobutylene fraction, hydrogenated

Cas Number:

93685-81-5

Molecular formula:

not applicable (a generic molecular formula cannot be provided for this specific UVCB substance)

IUPAC Name:

isododecane

Test material form:

liquid

Specific details on test material used for the study:

Test substance identified as LUPEROX 220 M 50
batch number: 512-9800-001
description: colourless liquid
storage conditions: at room temperature and protected from light
purity: 50.1 %
expiry date: September 1998

The test substance was used undiluted.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Sex, species, strain: male New Zealand White rabbits.
Justification of the test system : species generally accepted by regulatory authorities for this type of study.
Breeder: Elevage Cunicole de Val de Selle, 80160 Prouzel, France.
Number of animals and identification: three animals were used, as recommended by the international guidelines and taking into account that a good correlation of results can be obtained with either three or six animals. The animals were identified individually with a metal tag in the ear.
Weight: on the day of treatment, the animals had a mean body weight of 2.5 ± 0.2 kg.
Acclimatization: at least 5 days before the beginning of the· study.

The conditions in the animal room were set as follows:
temperature: 18 ± 3°C
relative humidity: 30 to 70%
light/dark cycle: 12h/12h
ventilation: approximately 12 cycles/hour of filtered, non-recycled air.
The temperature and relative humidity were under continuous control and recording. The records were checked daily and archived. In addition to these daily checks, the housing conditions and corresponding instrumentation and equipment were verified and calibrated at regular intervals.
The animals were housed individually in polystyrene cages (35 cm x 55 cm x 32 cm or 48.2 cm x 58 cm x 36.5 cm). Each cage was equipped with a food container and a water bottle.

Food and water
During the study, the animals had free access to 112 C pelleted diet (UAR, 9 1360 Villemoissonsur-Orge, France).
Each batch of food was analysed by the supplier for composition and contaminant levels.

Drinking water filtered by a FG Millipore membrane (0.22micron) was provided ad libitum.
Bacteriological and chemical analysis of the water and diet, including the detection of possible contaminants (pesticides, heavy metals and nitrosamines), are performed regularly by external laboratories.
The results of these analyses are archived at CIT.
No contaminants are known to be present in the diet or drinking water at levels which may be expected to interfere with or prejudice the outcome of the study.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.5 ml of the undiluted test substance
The untreated skin served as control

Duration of treatment / exposure:

3 minutes or 4 hours

Observation period:

The skin was examined approximately 1 hour, 24, 48 and 72 hours after removal of the dressing.

Number of animals:

3

Details on study design:

Preparation and selection of the animals
The day before treatment, both flanks of each animal were clipped using electric clippers and the skin of each animal was examined. Only animals with healthy intact skin were used.

Study design
The study design was established according to available information on the test substance and the OECD (No. 404) and EC (92/69/EEC, B.4) guidelines.
As possible irritant effects were anticipated, the test substance was evaluated in one animal (No. 01) in a first assay. The duration of exposure was 3 minutes on one flank and 4 hours on the other flank.
Since the treated animal was found dead on day 3, and as no severe cutaneous reactions were observed prior to death in this animal, the test. substance was applied for 4 hours to two other animals (Nos. 02 and 03) in a second assay.

Application of the test substance
The test substance was used undiluted.
Doses of 0.5 ml of the test substance were placed on a 6 cm^2 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 dressing and a restraining bandage.
The untreated skin served as control.
No residual test substance was observed on removal of the dressing.

CUTANEOUS EXAMINATIONS
The skin was examined following the OECD and EC guidelines:
- when there was no evidence of dermal irritation after 72 hours, the study was ended .
- when there was persistent cutaneous irritation after 72 hours, the observation period was extended to a maximum of 14 days (until day 15) in order to determine the progress of the lesions and their reversibility .
- when severe irritant effects were observed, the animals were killed on humane grounds.
Any change in the animals' behaviour was noted.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: erythema and oedema

Basis:

animal #1

Remarks:

3 minute exposure

Time point:

24/48 h

Remarks on result:

no indication of irritation

Remarks:

animal found dead on day 3 (48 hr)

Results 2

Irritation parameter:

other: erythema and oedema

Basis:

animal #1

Remarks:

4 hour exposure

Time point:

24/48 h

Remarks on result:

no indication of irritation

Remarks:

animal found dead on day 3 (48hr)

Results 3

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

2

Reversibility:

fully reversible

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Results 5

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.7

Max. score:

2

Reversibility:

fully reversible

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.7

Max. score:

2

Reversibility:

fully reversible

Irritant / corrosive response data:

After a 3-ininute exposure (one animal):
No cutaneous reactions were observed. The animal was found dead on day 3. Whether this death was attributable to treatment with the test substance or not could not be determined.
After a 4-hour exposure (three animals):
A very slight erythema (grade 1) was· noted on day 2 in the first treated animal which was found dead on day 3. A well-defined erythema (grade 2) was observed in the two other animals, from day 1 up to day 3 or 6; a very slight erythema (grade 1) was then recorded up to day 6 or 8, respectively. A slight oedema (grade 2) was observed in one of these animals on day 2. Dryness of the skin was noted from day 6 up to day 15 or from day 5 up to day 10.
Mean scores over 24, 48 and 72 hours for two animals were 2.0 and 1.7 for erythema and 0.7 and 0.0 for oedema.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the experimental conditions, the test substance LUPEROX 220 M 50 (batch No. ·512-9800-001 (MXL)) is slightly irritant when applied topically to rabbits. According to CLP, the results do not meet the criteria for classification (mean value of ≥ 2.3 for erythema/escha or for oedema in at least 2 of 3 tested animals from gradings at 24, 48 and 72 hrs).

Executive summary:

The potential of the test substance LUPEROX 220 M 50 (batch No. 512-9800-001 (MXL)) to induce skin irritation was evaluated in rabbits according to OECD (No. 404, 17th July 1992) and EC (92169/EEC, B.4, 31st July 1992) guidelines.

The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

Methods

The study design was established according to available information on the test substance and the above guidelines.

The test substance was applied in a first assay for periods of 3 minutes and 4 hours to one male New Zealand White rabbit.

Since the treated animal was found dead on day 3, and as no severe cutaneous reactions were observed prior to death in this animal, the test substance was applied for 4 hours to two other males in a second assay.

A single dose of 0.5 ml of the undiluted test substance was applied to the closely-clipped skin of one 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 the end of the observation period at the latest.

The mean values of the scores for erythema and oedema were calculated for the two surviving animals.

Results

After a 3-minute exposure (one animal):

No cutaneous reactions were observed. The animal was found dead on day 3. Whether this death was attributable to treatment with the test substance or not could not be determined.

After a 4-hour exposure (three animals):

A very slight erythema was noted on day 2 in the first treated animal which was found dead on day 3.

A well-defined erythema was observed in the two other animals, from day 1 up to day 3 or 6; a very slight erythema was then recorded up to day 6 or 8, respectively. A slight oedema was observed in one of these animals on day 2. Dryness of the skin was noted from day 6 up to day 15 or from day 5 up to day 10.

Mean scores over 24, 48 and 72 hours for two animals were 2.0 and 1.7 for erythema and 0.0 and 0.7 for oedema.

Conclusion

Under our experimental conditions, the test substance LUPEROX 220 M 50 (batch No. 512 -9800-001 (MXL)) is slightly irritant when applied topically to rabbits.