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Diss Factsheets

Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Equivalent to OECD 402. 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 402 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Chemical structure
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: 204-227 g; females: 145-157 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

Vehicle:
other: moistened
Details on dermal exposure:
The day before dosing, approximately 60% of the dorsal hair of all animals was closely shorn with fine electric clippers. Before application of the tst material, the skin was visually inspected to ensure that all micro-abrasions of the stratum corneum had healed.

The calculated dose was weighed onto a piece of aluminium foil lined with gauze and applied to the shorn skin. The foil was held in place by a double overwrap of waterproof adhesive tape.

After the 24 h exposure, the tape and foil were removed and the skin washed with warm dilute detergent solution and then dried.
Duration of exposure:
24 hours
Doses:
2000 mg/kg
No. of animals per sex per dose:
Five animals per sex
Control animals:
not required
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for signs of toxicity three times a day for the first three days and daily thereafter for the remainder of the 14 day observation period. Initial (Day 1), Day 7 and Day 14 body weights were recorded.
- Necropsy of survivors performed: necropsies were not conducted.

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 7.2.3:      Summary of Acute Dermal 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 (24 h) percutaneous LD50 of the test powder in rats was greater than 2000 mg/kg.
Executive summary:

Five rats per sex were dermally 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 dermal LD50 of the test material in rats was greater than 2000 mg/kg.