1,1'-(1,1,2,2-tetramethylethylene)dibenzene

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1993-02-23 to 1993-02-26

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

adopted May 12, 1981

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

84/449/EEC

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,1'-(1,1,2,2-tetramethylethylene)dibenzene

EC Number:

217-568-2

EC Name:

1,1'-(1,1,2,2-tetramethylethylene)dibenzene

Cas Number:

1889-67-4

Molecular formula:

C18H22

IUPAC Name:

(2,3-dimethyl-3-phenylbutan-2-yl)benzene

Test material form:

solid: flakes

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Broekman Institute, Someren, The Netherlands
- Age at study initiation: Approx. 12 weeks
- Weight at study initiation: 2410 - 2674 g
- Housing: Individually in labelled cages with perforated floors and equipped with an automatic drinking system.
- Diet: Standard laboratory rabbit diet (LKK-20, peller diameter 4mm, Hope Farms, Woerden, The Netherlands) approx. 100 g per day.
- Water: Free access to tap-water diluted with decalcified water.
- Acclimation period: at least five days before start of treatment under test conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): 55
- 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:

other: the untreated contralateral flank served as negative control.

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 g, using a moistened Scotchpak-non-woven patch.

Duration of treatment / exposure:

4 h

Observation period:

72 h

Number of animals:

3 male rabbits

Details on study design:

TEST SITE
- Area of exposure: dorsal
- coverage: 10 cm x 15 cm were shaved, treatment area 2 x 3 cm.
- Type of wrap if used: elastic bandage (Coban, 3M, St. Paul, USA)

REMOVAL OF TEST SUBSTANCE
- Washing: The remaining test substance was removed using a tissue moistened with tap-water and subsequently dried with a tissue.
- Time after start of exposure: 4 h

SCORING SYSTEM: according to OECD and EU Guidelines (Draize system).

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

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 5

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 6

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 7

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 8

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

No skin irritation was caused by the test substance after a 4 hour dermal application. There was no evidence of a corrosive effect on the skin.

Other effects:

No staining of the treated skin by the test substance was observed. No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

1,1'-(1,1,2,2-tetramethylethylene)dibenzene resulted in a primary irritation index of 0 (erythema and edema score over 24/48/72 h = 0), when applied to the intact rabbit skin.

Executive summary:

1,1'-(1,1,2,2-tetramethylethylene)dibenzene was applied onto shaved skin of three albino rabbits (New Zealand White) using semi-occlusive dressings for 4 hours, followed by four observations at approximately 1, 24, 48 and 72 hours after removal of the dressings and remaining test substance. The study was performed according to OECD 404 and Regulation (EC) No 440/2008 Method B.4. Under the conditions of this study, no skin irritation was caused by 1,1'-(1,1,2,2-tetramethylethylene)dibenzene and no corrosive effect occurred on the skin in any of the three rabbits. In the area of application, no staining of the treated skin by 1,1'-(1,1,2,2-tetramethylethylene)dibenzene was observed. No signs of intoxication were observed during the study period. 1,1'-(1,1,2,2-tetramethylethylene)dibenzene resulted in a primary irritation index of 0 (erythema and edema score over 24 /48/72 h = 0), when applied to the intact rabbit skin and is thus classified as not irritating to the skin.