2,6-di-tert-butyl-p-cresol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 12 to November 30, 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): Rhodianox BHT AP5
- Physical state: white crystals
- Lot/batch No.: OP 25007

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Iffa-Credo: Les Oncins, 69210 L´Arbresle, France
- Age at study initiation: 5-7 weeks old
- Weight at study initiation: males: 197-229 g; females: 149-183 g
- Housing: Individual housing in polycarbonate cages of type FI, and of internal dimensions 305 x 180 x 184 mm
- Diet (e.g. ad libitum): Rat-mouse pelleted complete maintenance diet, ad libitum.
- Water (e.g. ad libitum): Softened and filtered drinking water, ad libitum.
- Acclimation period: Minimum of one week before the beginning of treatment.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 ºC
- Humidity (%): 30-70%
- Air changes (per hr): Not documented
- Photoperiod (hrs dark / hrs light): a 12-hour light-dark cycle


IN-LIFE DATES: From November 12 to November 30, 1987

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

other: an aqueous dispersion at 10% (w/v) of gum Arabic

Details on dermal exposure:

TEST SITE
- % coverage: 10% of the total body surface area
- Type of wrap if used: The test material was held in contact with the skin with a bandage composed of a 10 cm wide adhesive and perforated tape, appied on a crimped gauze bandage covering the whole clipped area.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): The test material was wiped away by a rinsing with lukewarm water.
- Time after start of exposure:


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2.8 ml/kg of live bodyweight
- For solids, paste formed: The test material being under the form of crystals was reduced into a powder in a mortar and put under the form of a paste at 71.43 % w/v in an aqueous dispersion at 10% w/v of gum Arabic.

Duration of exposure:

24 hours

Doses:

Preliminary study: 1000 and 2000 mg/kg
Definitive study: 0 and 2000 mg/kg

No. of animals per sex per dose:

Preliminary study: 2 animals per sex per dose
Definitive study: 5 animals per sex

Control animals:

yes, concurrent vehicle

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortalities and abnormal clinical signs were recorded 15 minutes after administration of the test article, then 1, 2 and 4 hours later and daily for the 14 day study period. The daily observations took into account any changes to the hair, the treated skin, the eyes, they mucous membranes, the respiratory system, the circulatory system, the autonomous and central nervous systems, motor activity and behaviour. Special attention was paid when quivering, convulsions, salivation, diarrhea, apathy, sleep and coma were observed. The animals were weighed on Day 1, Day 8 and Day 15.
- Necropsy of survivors performed: yes
- Other examinations performed: The abdominal and thoracic cavities were opened and a special observation was performed on the following organs: liver, heart, kidneys, lungs. An examination of the skin was also carried out on the application site.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

None of the rats died.

Clinical signs:

other: There were no clinical signs observed.

Gross pathology:

There were no macroscopic findings.

Other findings:

There were no dermal reactions.

Any other information on results incl. tables

Table 7.2.3:      Summary of Acute Dermal Toxicity

Males			Females
Dose	Mortality	Time of death	Dose	Mortality	Time of death
0 mg/kg	0/5	--	0 mg/kg	0/5	--
2000 mg/kg	0/5	--	2000 mg/kg	0/5	--

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to EU criteria. Since the GHS has an additional category, the available information does not allow to determine if the subtance would be classified in category V or if the GHS criteria is not met.

Conclusions:

The acute dermal LD50 in the Sprague-Dawley rat was greater than 2000 mg/kg-bw.

Executive summary:

The test material was reduced to a powder and put under the form of a paste at 71.43 % w/v in an aqueous dispersion at 10% w/v of gum Arabic. The test material was applied to the skin of five animals per sex per dose. The acute dermal LD50 in the Sprague-Dawley rat was greater than 2000 mg/kg-bw.