Reaction mass of 2,6-di-tert-butylphenol and 2,4,6-tri-tert-butylphenol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From February 18 to March 5, 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: There are no deviations from the OECD Guideline 402 (Acute Dermal Toxicity). No GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,4,6-tri-tert-butylphenol; 2,6-di-tert-butylphenol

EC Number:

907-745-9

Molecular formula:

Not applicable - Multiconstituent substance

IUPAC Name:

2,4,6-tri-tert-butylphenol; 2,6-di-tert-butylphenol

Details on test material:

- Physical state: Clear pale yellow liquid on receipt, but solidified on storage at 0-5 ºC.
- Storage condition of test material: On its arrival the test substance was stored in the dark at ambient temperature. Following receipt of further information, the storage conditions were changed on 13th September 1990 to in the dark at between 0-5 ºC.

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River U.K. Ltd.
- Age at study initiation: 9-11 weeks
- Weight at study initiation: males: 219-262 g; females: 142-166 g
- Housing: Single sex groups of up to three rats in cages with stainless steel wire-mesh walls, floors and tops (33 cm x 22 cm x 16 cm). Paper-lined trays for excreta were placed beneath each cage and changes three times weekly.
- Diet (e.g. ad libitum): Pelleted diet (LAD1, Special Diet Services Ltd.), ad libitum.
- Water (e.g. ad libitum): from the public supply, ad libitum.
- Acclimation period: The animals were quarantined for a minimum of four days in a non-barrier animal room with access restricted to essential personnel. At least five days before dosing the animals were rehoused.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 ºC
- Humidity (%): 30-70%
- Air changes (per hr): not documented.
- Photoperiod (hrs dark / hrs light): 12 hour day and 12 hour night


IN-LIFE DATES: From February 18 to March 5, 1991

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

On the day before dosing the dorsal fur was removed from the animals using electric clippers. A single dose of the undiluted test material was applied to the skin. The test material was held in place with a gauze dressing (approx 6 x 8 cm) covered with waterproof adhesive tape.

Duration of exposure:

Following a 24 hour exposure the dressings were removed, the skin washed with warm dilute detergent solution and dried.

Doses:

Animals received a single dermal application at 2000 mg/kg. The undiluted test material was administered at a dose volume of 2.13 ml/kg.

No. of animals per sex per dose:

Five animals per sex per dose

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: A detailed clinical examination was made five times on the day of dosing and twice daily thereafter for the remainder of the 14 day observation period. The initial (Day 1), Day 8 and Day 15 bodyweights were recorded and changes in bodyweight calculated.
- Necropsy performed: no

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

None of the rats died.

Clinical signs:

other: There were no signs of systemic reaction to treatment. Sites of application of the test material showed erythema and, in one case, oedema from Day 2 and yellow discolouration from Day 3. The inflammatory reaction resolved by Day 5 and the treated skin was

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute dermal LD50 for the test substance is greater than 2000 mg/kg.

Executive summary:

Five rats per sex were dosed at 2000 mg/kg. Following a 24 hour exposure the dressings were removed. A detailed clinical examination was made five times on the day of dosing and twice daily thereafter for the remainder of the 14 day observation period. The initial (Day 1), Day 8 and Day 15 bodyweights were recorded and changes in bodyweight calculated. Animals surviving to the end of the study were killed by carbon dioxide asphyxiation. None of the rats died. The acute dermal LD50 for the test substance is greater than 2000 mg/kg.