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

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: According to OECD 404. GLP study. The dose level applied to the skin of the animals was 250 mg instead of 500 mg for solids, as recommended in the guideline. However, it is considered that this deviation does not affect the outcome of the study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

(However, it is considered that this deviation does not affect the outcome of the study).

GLP compliance:

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:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Sittingbourne Research Centre Breeding unit
- Age at study initiation: 4-9 months old
- Weight at study initiation: males: 3888-4462 g; females: 4966-4994 g
- Housing: Animals were singly housed in hanging, stainless-steel cages with all-mesh floors and tops and half-mesh fronts; each cage measured 67 cm x 43 cm x 45 cm.
- Diet (e.g. ad libitum): Standard Rabbit Diet, S.Q.C., Special Diet Services Ltd., Essex, ad libitum.
- Water (e.g. ad libitum): Filtered from the public supply , ad libitum.
- Acclimation period: At least, two weeks.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16-19 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).

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

other: moistened with water

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 250 mg

Duration of treatment / exposure:

4 hours

Observation period:

30 minutes after the removal of the patch and at 24, 48 and 72 hours and 7 days after patch removal.

Number of animals:

Three per sex

Details on study design:

TEST SITE
- Area of exposure: Dorsal hair between the shoulders and hindquarters was closely shorn with fine electric clippers. A 2 cm x 2 cm lint patch was applied.
- Type of wrap if used: The patch and surrounding skin were covered by a single layer of gauze and held in place by means of an elastic adhesive bandage.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): After 4 hours the wrapping and patch were removed and the test site washed with water and gently dried.


SCORING SYSTEM: Erythema and oedema on a graded scale of 0 to 4.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable

Any other information on results incl. tables

Table 7.3.1: Dermal irritation scores

	Erythema						Oedema
Animal No	1	2	3	4	5	6	1	2	3	4	5	6
after 4 h	0	0	0	0	0	0	0	0	0	0	0	0
after 24 h	0	0	0	0	0	0	0	0	0	0	0	0
after 48 h	0	0	0	0	0	0	0	0	0	0	0	0
after 72 h	0	0	0	0	0	0	0	0	0	0	0	0
after 7 days	0	0	0	0	0	0	0	0	0	0	0	0
Mean score 24 – 72 h	0.0						0.0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In the 4 hour rabbit skin irritancy test, the test material caused no skin reactions and is therefore not a skin irritant.

Executive summary:

Six New Zealand White rabbits (3 per sex) were exposed via the dermal route to 250 mg of the test substance. After a 4 hour exposure the dresssings were removed, the skin washed with water and dried. After treatment, animals were examined for erythema, oedema and other lesions at 4, 24, 48 and 72 hours and at 7 days after patch removal. The test material caused no skin reactions and was therefore considered as not irritanting to skin.