2-(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:

07-07-1992 to 23-07-1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline 404 study, performed to GLP

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:

o-tert amylphenol

IUPAC Name:

o-tert amylphenol

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Phenol, 2-(1,1-Dimethylpropyl)
- Physical state: pale straw coloured liquid
- Supplied by Sandoz Chemicals LTD.
- Storage condition of test material: room temperature in a sealed opaque plastic container

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: David Percival Ltd., Moston, Sandbach, Cheshire, U.K.
- Age at study initiation: 12-16 weeks
- Weight at study initiation: 2.77 - 3.18 kg
- Housing: individually housed in suspended metal cages
- Diet (ad libitum): Spillers Rabbit Diet, Dalgety Agriculture Ltd., Almondsbury, Bristol
- Mains drinking water (ad libitum)
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 23°C
- Humidity (%): 53 - 68%.
- Air changes (per hr): 15 changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours darkness

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 ml neat liquid applied under a 2.5 x 2.5 cm gauze semiocclusive dressing.

Duration of treatment / exposure:

4 hours and 3 minutes

Observation period:

Approximately one hour following 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 Draize method.

Number of animals:

n=3 rabbits (4 hour exposure)
n=3 rabbits (3 minutes exposure)

Details on study design:

TEST SITE
- Area of exposure: 2.5 x 2.5 cm

- Type of wrap if used: gauze patch secured in position with a strip of surgical adhesive tape (BLENOERM: approximate size 2.5 cm x 4.0 cm), the trunk of each rabbit was wrapped in an elasticated corset (TUBIGRIP).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): residual test material removed by gentle swabbing with cotton wool soaked in diethyl ether

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Time point:

other: 4 hours

Remarks on result:

other: Erythema could not be scored due to corrosive burns on the site of application

Results 2

Irritation parameter:

erythema score

Time point:

other: 3 minutes

Remarks on result:

other: The material was corrosive

Irritant / corrosive response data:

4 hour exposure:
Moderate to severe erythema and severe oedema were noted at all treated skin sites one hour after patch removal. Evaluation of the erythema and oedema was not possible at the 72-hour and 7 day observations due to the presence of other adverse dermal reactions. These were haemorrhage of the dermal capillaries, brown discolouration of the epidermis (possible necrosis), loss of skin elasticity and flexibility, thickening of the skin, reduced re-growth of fur and scabbing. Well-defined or moderate erythema occasionally surrounded the scabs, with oedema occasionally extending beyond the sites of application during the study. These reactions were considered to be indicative of corrosion.

3 minute exposure:
Well-defined erythema and slight to moderate oedema were noted at all treated skin sites one hour after patch removal. Well-defined erythema and and slight to severe oedema at 24, 48 and 72 hour observations. Other adverse dermal reactions noted at one treated skin site at the 72-hour observation were loss of skin elasticity and flexibility and thickening of the skin. The reaction extended beyond this treated skin site at the 24 to 72-hour observations. Crust formation or desquamation was noted at all treated skin sites seven days after treatment.

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

o-tert amylphenol is corrosive when applied as a neat liquid to the clipped dorsal skin of New Zealand white rabbits, for 4 hours or 3 minutes.

Executive summary:

In an OECD guideline study, o-tert amylphenol is corrosive when applied as 0.5ml of a neat liquid to the clipped dorsal skin of New Zealand white rabbits (area 2.5 x 2.5cm), for both 4 hours or 3 minutes.