6,6'-di-tert-butyl-4,4'-butylidenedi-m-cresol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

20 - 27 January 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Good quality study data prepared according to international guidelines in accordance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

125643-61-0

Cas Number:

125643-61-0

IUPAC Name:

125643-61-0

Constituent 2

Reference substance name:

NAUGALUBE 531

IUPAC Name:

NAUGALUBE 531

Test material form:

liquid: viscous

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Three New Zealand White rabbits supplied by David Percival Ltd, Moston, Sandbach, Cheshire, UK were used. At the start of the study the animals weighed 2.42 to 2.94 kg and were twelve to sixteen weeks old. After a minimum acclimatisation period of five days each animal was given a number unique within the study which was written with a black indelible marker-pen on the inner surface of the ear and on the cage label.

The animals were individually housed in suspended metal cages. Free access to mains drinking water and food (STANRAB SQC Rabbit Diet, Special Diets Services Ltd, Witham, Essex, UK) was allowed throughout the study.

The animal room was maintained at a temperature of 17 to 19" C and relative humidity of 46 to 59%. The rate of air exchange was approximately fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light and twelve hours darkness.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

A quantity of 0.5 ml of the test material was introduced under a 2.5 cm x 2.5 cm cotton gauze patch and placed in position on the shorn skin. The patch was secured in position with a strip of surgical adhesive tape (BLENDERM: approximate size 2.5 cm x 4.0 cm). To prevent the animals interfering with the patches, the trunk of each rabbit was wrapped in an elasticated corset (TUBIGRIP) and the animals were returned to their cages for the duration of the exposure period.

Duration of treatment / exposure:

Four hours after application the corset and patches were removed from each animal and any residual test material removed by gentle swabbing with cotton wool soaked in 74% Industrial Methylated Spirits.

Observation period:

Approximately one hour following the removal of the patches, and 24, 48 and 72 hours later, the test sites were examined for evidence of primary irritation and scored according to the following scale from Draize J H, (1 977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.31.

Number of animals:

3 animals

Details on study design:

The scores for erythema and oedema at the 24 and 72-hour readings were totalled for the three test rabbits (12 values) and this total was divided by six to give the primary irritation index of the test material. The test material was classified according to the following scheme devised by Draize J H (1959) "Dermal Toxicity" In: Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics. Association of Food and Drug Officials of the United States, Austin, Texas, p.47

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

72 h

Score:

1.2

Max. score:

2

Reversibility:

fully reversible

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test substance produced a primary irritation index of 1.2 and was classified as MILD IRRITANT to rabbit skin according to the Draize classification scheme. No corrosive effects were noted.

Executive summary:

A study was performed to assess the irritancy potential of the test material to the skin of the New Zealand White rabbit. The method used followed the recommendations of the OECD Guidelines for Testing of Chemicals No. 404 "Acute Dermal Irritation/Corrosion" (adopted 17 July 1992).

A single 4-hour, semi-occluded application of the test material to the intact skin of three rabbits produced very slight to well-defined erythema and very slight oedema. All treated skin sites appeared normal at the 7-day observation.

The test material produced a primary irritation index of 1.2 and was classified as a mild irritant to rabbit skin according to the Draize classification scheme. No corrosive effects were noted.