2,2',6,6'-tetra-tert-butyl-4,4'-methylenediphenol

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Equivalent to OECD 401. GLP study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2',6,6'-tetra-tert-butyl-4,4'-methylenediphenol

EC Number:

204-279-1

EC Name:

2,2',6,6'-tetra-tert-butyl-4,4'-methylenediphenol

Cas Number:

118-82-1

Molecular formula:

C29H44O2

IUPAC Name:

2,6-di-tert-butyl-4-[(3,5-di-tert-butyl-4-hydroxyphenyl)methyl]phenol

Details on test material:

- Physical state: Pale yellow powder
- Analytical purity: 99.04%
- Lot/batch No.: 5/87; Indent 9200/9622
- Storage condition of test material: Following its arrival in Compound Control this test substance was stored in the dark at ambient temperature.
- Stability: Infra-red spectra of the test substance were taken. There were no significant differences between the spectra and so, on this basis, the test substance was judged to have been stable for the duration of this study.

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 old
- Weight at study initiation: males: 181-197 g; females: 132-142 g
- Fasting period before study: All animals were fasted overnight (18 hours).
- Housing: On arrival, animals were housed in single sex groups of up to 12 to a cage; each cage measured 56 cm x 38 cm x 18 cm. Prior to experimentation the animals were rehoused (as single sex groups of four) in cages with stainless-steel wire-mesh floors and tops; each cage measured 38 cm x 25 cm x 18 cm. At least two days before dosing, the rats were housed in groups of two or three animals of the same sex per cage.
- Diet (e.g. ad libitum): PRD, Labsure Animal Foods, Dorset, ad libitum.
- Water (e.g. ad libitum): Filtered water from the public supply, ad libitum.
- Acclimation period: Two weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 ºC
- Humidity (%): Not documented.
- Air changes (per hr): Not documented.
- Photoperiod (hrs dark / hrs light): Lighting was automatically switched on for the day (06.00 to 18.00 hours GMT) and off for the night (18.00 to 06.00 hours GMT)

Administration / exposure

Route of administration:

other: intraoesophageal intubation using a ballpoint needle fitted to a syringe

Vehicle:

corn oil

Details on oral exposure:

The test material was administered as a 20% m/v suspension in corn oil

Doses:

2000 mg/kg

No. of animals per sex per dose:

Five animals per sex

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for clinical signs three times a day for the first three days and daily thereafter. The initial (Day 1), Day 7 and Day 14 body weights were recorded.
- Necropsy of survivors performed: necropsy was not performed.

Results and discussion

Effect levels

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.

Any other information on results incl. tables

Table 7.2.1:      Summary of Acute Oral Toxicity

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

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral LD50 of the test material in rats administered as a 20% (m/v) suspension in corn oil was greater than 2000 mg/kg.

Executive summary:

Five rats per sex were orally dosed at 2000 mg/kg. Animals were observed for clinical signs three times a day for the first three days and daily thereafter for the remainder of the 14 day observation period. The initial (Day 1), Day 7 and Day 14 body weights were recorded. None of the rats died. There were no clinical signs observed. The acute oral LD50 of the test material in rats administered as a 20% (m/v) suspension in corn oil was greater than 2000 mg/kg.