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

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2011-09-22 to 2011-11-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

24 February 1997

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Version / remarks:

30 May 2008

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

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:

other: solid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl:CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH, 97633 Sulzfeld, Germany
- Age at study initiation: Approximately 8 weeks (males) and 12 weeks (females)
- Weight at study initiation: males: 271 - 288 g; females: 222 - 244 g
- Fasting period before study: no
- Housing: Single caging in Makrolon cages type III (37.5 cm x 21.5 cm bottom area, 18 cm height). Wire mesh lids. Sanitation of cages once a week
- Diet: Ssniff R/M-H maintenance diet for rats and mice (item V1534-300) ad libitum, supplied by Ssniff Spezialdiäten GmbH, 59494 Soest, Germany
- Water: Tap water, from an automatic watering system, ad libitum
- Acclimation period: At least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: Mean of 20.85 °C (continuous control and recording)
- Humidity: Mean of 41.49 % (continuous control and recording)
- Air changes: 12 per hour.
- Photoperiod: Artificial light from 6 a.m. to 6 p.m.

IN-LIFE DATES: From: 2011-10-11 To: 2011-10-25

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 6.5 x 8 cm
- % coverage: 10 % of estimated body surface
- Type of wrap if used: semi-occlusive dressing (Fixomull Stretch, Fa. Beiersdorf)

REMOVAL OF TEST SUBSTANCE
- Washing: Residual test substance was wiped off using wet cellulose tissue
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount applied: The amounts of the test substance were calculated and weighed for each individual using the body weights determined on the day of the administration
- For solids, paste formed: no

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations were performed 0 - 0.5, > 0.5 - 1, > 1 - 2, > 2 - 4 and > 4 - 6 hours after administration of the test substance (p.a.) and then at least once a day for a total of 2 weeks.
Body weights were determined
• before administration.
• 7 days p.a.
• 14 days p.a.
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

All animals survived until the scheduled termination of the study.

Clinical signs:

other: General findings: All animals did not show any clinical signs during the entire observation period. Observations of skin condition: Exposed skin was not found to be altered by the test substance.

Gross pathology:

No abnormal findings were made in the animals at terminal necropsy.

Other findings:

No noteworthy sex difference in the response to the test substance was derived from clinical observations or post-mortem findings.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No local or systemic toxic effects related to administration of the test substance were noted from clinical observations or post mortem examination at a dose of 2000 mg of the test substance per kg body weight. No mortality occurred.

Executive summary:

The test item 1,1'-(1,1,2,2-tetramethylethylene)dibenzene was tested in an acute dermal toxicity study in rats according to OECD guideline 402 and EU method B.3. The test item was administered once topically on an area of approximately 6.5 cm x 8 cm on the dorsal thoracic region of 5 male and 5 female Sprague Dawley rats. The dose was 2000 mg per kg body weight. A cellulose patch with the calculated amount of the test substance on the surface and soaked with deionised water to get optimal contact with the skin, was applied to the test site and held in place by fixing marginally with non-irritating tape. The test site was covered by a semi-occlusive dressing. The duration of the exposure was 24 hours. No local or systemic toxic effects related to administration of the test substance were noted from clinical observations or post-mortem examination at a dose of 2000 mg of the test substance per kg body weight. No mortality occurred. Therefore, the LD50 dermal was estimated to be > 2000 mg /kg body weight.