2,6-bis(1,1-dimethylethyl)-4-(phenylenemethylene)cyclohexa-2,5-dien-1-one

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-02-23 - 1998-04-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD TG 402) performed under GLP

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 402 (Acute Dermal Toxicity)

Version / remarks:

adopted on 24th February 1987

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OTS 798.1100 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

429-460-4

EC Name:

-

Cas Number:

7078-98-0

Molecular formula:

C21 H26 O

IUPAC Name:

2,6-bis(1,1-dimethylethyl)-4-(phenylenemethylene)cyclohexa-2,5-dien-1-one

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Ace Animals, Boyertown, PA, U.S.A. (on 2/17/98)
- Age at study initiation: bom the weeks of 11/30 through 12/14/97
- Weight at study initiation: 2.1 – 2.7 kg (males), 2.0 – 2.4 kg (females)
- Housing: 1/cage in suspended wire cages
- Diet: Fresh Purina Rabbit Chow, provided daily
- Water: ad libitum
- Acclimation period: at least 1 week

ENVIRONMENTAL CONDITIONS
- Temperature: temperature-controlled
- Humidity: Not indicated
- Photoperiod: 12 hours dark / 12 hours light
- Other: Room was kept clean and vermin free

IN-LIFE DATES: From: 1998-03-02 To: 1998-03-15

Administration / exposure

Type of coverage:

occlusive

Vehicle:

physiological saline

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal area of the trunk of the animals
- Coverage: Approximately 10 % of the total body surface
- On test day 1, the test item was applied under a 4 layered surgical gauze patch approximately 10x15 cm. The patch and test item were moistened with 1.5 mL of saline. Gentle pressure was applied to the gauze.
- Type of wrap: The torso was wrapped with plastic which was secured with non-irritating tape.

REMOVAL OF TEST SUBSTANCE
- Washing: Residual test item was gently wiped from the treated site before observation

TEST MATERIAL
- Amount applied: 2000 mg/kg bw (based on dry weight)
- Constant volume or concentration used: Yes

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 rabbits

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Observation of test sites: 30 to 60 minutes post patch removal and again at 24, 48 and 72 hours post patch removal and on days 5, 7,10 and 14 (using numerical Draize scoring code)
- Frequency of further observations and weighing:
Toxicity and pharmacological effects: 1, 2 and 4 hours postdose and once daily for 14 days
Mortality: Twice daily for 14 days
Body weights: Pretest and on days 3, 7 and 14 or at death.
- Necropsy of survivors performed: yes

Statistics:

No statistical analysis was used.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

All animals survived the 2000 mg/kg bw dermal application.

Clinical signs:

There were no abnormal systemic signs noted during the observation period.

Body weight:

Body weight changes were normal in 8/10 animals. One male and one female lost weight at some time during the observation period.

Gross pathology:

Necropsy results were normal in 7/10 animals. Kidney abnormalities were noted in two males and treated skin abnormalities in one female.

Other findings:

- Other observations: Dermal reactions were absent to well defined on day 1, absent to slight on day 2, absent to well defined on day 3, absent to moderate on days 4 and 5, and absent to well defined on day 7. By days 10 and 14, dermal reactions were absent to slight.

Applicant's summary and conclusion

Interpretation of results:

practically nontoxic

Remarks:

Migrated information Criteria used for interpretation of results: EU