p-(1,1-dimethylpropyl)phenol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992-07-09 to 1992-07-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

p-(1,1-dimethylpropyl)phenol

EC Number:

201-280-9

EC Name:

p-(1,1-dimethylpropyl)phenol

Cas Number:

80-46-6

Molecular formula:

C11H16O

IUPAC Name:

4-(2-methylbutan-2-yl)phenol

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): phenol, 4-(1,1-dimethylpropyl)-
- Lot/batch No.: 20409018

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Six New Zealand White rabbits were supplied by David Percival Ltd., Moston, Sandbach, Cheshire, U.K. At the start of the study the animals weighed 2.54 - 2.99 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 (Spillers Rabbit Diet, Dalgety
Agriculture Ltd., Almondsbury, Bristol, U.K.) was allowed throughout the study.
The animal room was maintained at a temperature of 18 - 23°C and
relative humidity of 54 - 70%. The rate of air exchange was approximately IS changes per hour and the lighting was controlled by a time switch to give continuous 12 hours light and 12 hours darkness.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

A quantity of 0.5g of the test material, moistened with 0.5 ml of distilled water, was introduced under a 2.5 cm x 2.5 cm gauze patch and placed in
position on the shorn skin.

Duration of treatment / exposure:

4 hours or 3 minutes
Area applied: 2.5 cm x 2.5 cm

Observation period:

1 hour after removal of the patch, then 24, 28 and 72 hours afterwards the skin was examined for evidence of primary irritation and scored
according to the scale in Draize J.H. (1959) Association of Food and Drug Officials of the United states, Austin, Texas, "The Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics"

Number of animals:

2 males and 1 female (4hour exposure group)
2 males and 1 female (3 minute exposure group)

Details on study design:

0.5g of the test material, moistened with 0.5 ml of distilled water applied for 4 hours to the shaved back area of 2 males and 1 female.

Results and discussion

In vivo

Results

Irritation parameter:

other:

Basis:

animal #3

Time point:

other: 4 hours

Reversibility:

not reversible

Remarks on result:

other: Corrosive

Irritant / corrosive response data:

4 hour exposure period
Green-coloured necrosis and severe oedema were noted at one treated skin site one and 24 hours after treatment. Moderate erythema
surrounded the other skin reactions at the 24-hour observation. Adverse reactions prevented accurate evaluation of erythema and
oedema at this treated skin site at the 48 and 72 hour and 7-day observations. The reactions included a hardened dark brown/blackcoloured
scab surrounded by moderate erythema, dried blood, scar tissue, thickening of the skin, glossy skin and reduced re-growth of
fur. Adverse reactions noted at this treated skin site at the 14- day observation were scar tissue, glossy skin and reduced re-growth
of fur. Scar tissue is indicative of full thickness destruction and is therefore a sign of corrosion. Very slight to well-defined erythema and slight
oedema were noted at two treated skin sites one hour after patch removal with well-defined erythema and slight oedema at the 24 and 48-hour
observations and well-defined to moderate to severe erythema and very slight to slight oedema at the 72-hour observation. Crust formation was noted at one treated skin site at the 7-day observation. A hardened light brown-coloured scab prevented accurate evaluation of erythema and
oedema at one treated skin site at the 7-day observation. Desquamation and reduced regrowth of fur' were noted at this treated skin site at the
14-day observation.

3-Minute Exposure Period
Very slight erythema was noted at one treated skin site one and 24 hours after patch removal.
All treated skin sites appeared normal 48 hours after treatment.

Applicant's summary and conclusion

Interpretation of results:

corrosive

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The test material, PHENOL,4-(I,I-DIMETHVLPROPVL)-, was classified as CORROSIVE according to EEC labelling regulations.

Executive summary:

In an acute dermal irritation study, p-tert amylphenol was applied 0.5g in a 0.5 ml water suspension to the dorsal skin (2.5cm x 2.5cm) of New Zealand white rabbits (2 males; 1 female) for 4 hours. The test material was found to be corrosive.