Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 2-ethylhexyl ester

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From June 13th, 1989 to June 16th, 1989.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981

Deviations:

no

Principles of method if other than guideline:

The study was performed according to the OECD TG 404 and to GLP, however with following deviation: testing was conducted under occlusive conditions instead of semiocclusive as recommended by the guideline.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

406-040-9

EC Name:

-

Cas Number:

125643-61-0

Molecular formula:

C24-26 H40-44 O3

IUPAC Name:

C7-9-(branched)-alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate

Details on test material:

Physical properties: yellow liquid, insoluble in water
Test material received: May 18, 1989

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Kleintierfarm Madoerin AG, CH-4414 Fuellinsdorf
- Age at study initiation: approximately 12-14 weeks
- Weight at study initiation: 2290-2380 g
- Housing: individually in metal cages (and identified by individually numbered ear tags)
- Diet: standard rabbit pellet (Nafag No. 814, Gossau, Switzerland) ad libitum
- Water: fresh water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20 +/- 3°C
- Humidity: 30-70%
- Photoperiod (hrs dark / hrs light): 12h / 12h

All batches of the diet are assayed for nutritive ingredients and contaminant level by the manufacturer.
The drinking water quality fulfilled the critical parameters in the specification of the "Schweizerisches Lebensmittelbuch" (Edition 1972).

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: A control gauze patch moistened with distilled water was applied to the contralateral flank.

Amount / concentration applied:

A gauze patch (approx. 12-16 cm ) bearing 0.5 mL of the test substance was applied to the right flank of each animal. The patches were loosely covered with an aluminum foil and held in place for 4 hours by an adhesive tape (Isoplast, Isoplast AG, CH-5200 Brugg).

Duration of treatment / exposure:

4 hours

Observation period:

The skin reactions were evaluated 1, 24, 48, and 72 hours after removing the gauze patches; skin reaction was assessed according to the OECD scoring system. Moreover, the animals were checked daily for systemic symptoms and mortality.

Number of animals:

3 male animals.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

n = 3

Time point:

24/48/72 h

Score:

0.1

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: Erythema graded 1 was seen in all 3 animals at reading time point 1 hour and persisted until 24 hours in only one case. After 48 hours, recovery was complete.

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

n = 3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: None of the animals showed edema.

Irritant / corrosive response data:

The substance applied for 4 hours to the skin of rabbit under occlusive conditions induced very slight erythema in all 3 animals but no edema. Erythema was seen at reading time point 1 hour following removal of the dressing and was graded 1(max. 4). At reading time point 24 hour, very slight erythema persisted in one of the 3 animals. At reading time point 48 hour, reversibility was completed in all 3 animals.

Other effects:

None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the experimental conditions employed the test article induced minimal erythema reactions well below the threshold of significance when applied to the clipped albino rabbit skin.

Executive summary:

The substance was applied for 4 hours to the skin of 3 male rabbits according to the OECD TG 404, but under occlusive conditions. The treatment induced very slight erythema in all 3 animals but no edema. Erythema was seen at reading time point 1 hour following removal of the dressing and was graded 1(max. 4). At reading time point 24 hour, very slight erythema persisted in one of the 3 animals. At reading time point 48 hour, reversibility was completed in all 3 animals. Based on the scoring of the skin findings as recommended by the OECD guideline, the test item was not irritating to the skin of rabbit.