Bis(α,α-dimethylbenzyl) 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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Bis(α,α-dimethylbenzyl) peroxide

EC Number:

201-279-3

EC Name:

Bis(α,α-dimethylbenzyl) peroxide

Cas Number:

80-43-3

Molecular formula:

C18H22O2

IUPAC Name:

1,1'-(dioxydipropane-2,2-diyl)dibenzene

Details on test material:

- Name of test material (as cited in study report): Perkadox BC (Dicumylperoxide)
- Substance type: organic
- Physical state: white crystalline powder
- Analytical purity: 99.61%
- Impurities (identity and concentrations): not specified
- Purity test date: 09.06.1992
- Lot/batch No.: 041920580858
- Storage condition of test material: in refrigerator
- Other: certifcate of analysis attached in report

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Rosemead Rabbits, Rosemead, Waltham Abbey, Essex, England
- Age at study initiation: 3.5 to 4 months
- Weight at study initiation: 2.9 to 3.12 kg
- Housing: individually
- Diet: standard pelleted rabbit diet (SQC Rabbit Diet, Special Diets Services Ltd), ad libitum
- Water: Tap water, ad libitum
- Acclimation period: not specified (based on infromation in report assumed to be more than a week)


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-22 °C
- Humidity (%): 45-56%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g

Duration of treatment / exposure:

4 h

Observation period:

72 h

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 6x6 cm
- Type of wrap if used: unmedicated gauze (3x2cm), held in place on the left site by strips of blenderm; right site, acting as a control, was covered by a similar semi-occlusive dressing but otherwise remained untreated

REMOVAL OF TEST SUBSTANCE
- Washing (if done): warm water
- Time after start of exposure: after 4h

SCORING SYSTEM: according to Draize

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.6

Max. score:

4

Reversibility:

fully reversible within: 72h

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 48 h

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 48 h

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

See table below.

Any other information on results incl. tables

Table 1: Skin irritation scores according to Draize

				Response
	Time of observation	Rabbit No.
		1	2	3
Erythema
	1 h	0	1	1
	24 h	0	1	1
	48 h	0	1	0
	72 h	0	0	0
Edema
	1 h	0	0	0
	24 h	0	1	0
	48 h	0	0	0
	72 h	0	0	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the result of the study, the substance was not irritating when tested on rabbit skin.

Executive summary:

In a primary dermal irritation study (OECD guideline 404), three male New Zealand white rabbits were dermally exposed to 0.5 mg of the test item for 4 hours to a body surface area of 6 cm² under semi-occlusive conditions. Animals then were observed for 1, 24, 48 and 72 hours after removal of the dressings and test substance. The test item did not cause any skin effects, except very slight erythema observed in two rabbits during the first 24 h following bandage removal, continuing in one rabbit after 48 hours. Very slight oedema was evident at one test site at the 24 h observation. The test site of both these rabbits was overtly normal at the 72-h examination. Based on the results, the test item is considered to be non-irritating.