Phenol, dodecyl-, branched

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24th May to 7th June 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Similar to OECD guideline and conducted to GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

not specified

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Phenol, dodecyl-, branched

EC Number:

310-154-3

EC Name:

Phenol, dodecyl-, branched

Cas Number:

121158-58-5

Molecular formula:

Not appropriate. UVCB substance

IUPAC Name:

4-(3,4,5,6-tetramethyloctan-2-yl)phenol

Details on test material:

Composition data on the test material is held by the sponsor. The test material was received from the sponsor on May 16, 1988 and stored at ambient
temperature. In the opinion of the sponsor, the test material is stable under the recommended storage conditions.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: R and R Rabbitry, Stanwood, Washington
- Age at study initiation: The animals were 26-28 weeks old when dosed.
- Housing: The animals were housed individually in support bar-bottom cages in an air-conditioned room.
- Diet (e.g. ad libitum): The animals were fed a daily ration of Purina Certified High Fiber Rabbit Chow #5325
- Water (e.g. ad libitum): Free access to water.
- Acclimation period: Conditioning period of 18 weeks before dosing

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22 °C
- Humidity (%): 58-83%
- Photoperiod (hrs dark / hrs light): The photoperiod was a 12-hour light/dark cycle.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: Animals were shaved and had 2 intact and 2 abraded sites

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:

4 hours

Observation period:

1, 24, 48 & 72 hours and then 7 & 14 days after treatment.

Number of animals:

6 females per dose

Details on study design:

TEST SITE
The fur on the backs of six rabbits was clipped the day before dosing. One-half milliliter of the test material was applied to each of two intact and two abraded sites on the back of each rabbit. Epidermal abrasions (cross-hatching) were made with a hypodermic needle penetrating the stratum corneum over areas of approximately one square inch. After application, each treated site was covered with a gauze patch secured by porous tape. The trunk of each animal was loosely wrapped in a sheet of plastic film, and paper towels were wrapped around the plastic to prevent tearing. A collar was also placed on each animal to protect the wrappings during the exposure period.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After a four-hour exposure period, the wrappings and collars were removed, and the skin was wiped with gauze pads moistened with mineral oil, followed by dry gauze to remove any remaining test material.
- Time after start of exposure: 4 hours

SCORING SYSTEM:
Irritation was scored at 1, 24, 48, and 72 hours after removal of the test material and at 7 and 14 days, using a modified scoring method of Draize et al.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Intact skin

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

48 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Intact skin

Results 3

Irritation parameter:

erythema score

Basis:

mean

Time point:

72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Intact skin

Results 4

Irritation parameter:

edema score

Basis:

mean

Time point:

24 h

Score:

3.4

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Intact skin

Results 5

Irritation parameter:

edema score

Basis:

mean

Time point:

48 h

Score:

2.6

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Intact skin

Results 6

Irritation parameter:

edema score

Basis:

mean

Time point:

72 h

Score:

2.8

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Intact skin

Results 7

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

24/48/72 h

Score:

6.2

Irritant / corrosive response data:

The test material caused well-defined to severe erythema with no to moderate edema within one hour after unwrapping. Irritation increased to severe erythema and eschar formation with well-defined to severe edema at 24 through 72 hours. Cracking was observed on one animal at 72 hours. Severe erythema, eschar, cracking, a thin layer of light brown necrotic skin and thick light brown flakes were present on Day 7 with slight edema observed in one animal. At 14 days, well-defined to severe erythema, with eschar, a thin layer of light brown necrotic skin, thick light brown flakes, sloughing, alopecia and thin fur regrowth were present. There were no consistent differences between intact and abraded skin.

Other effects:

Microscopic findings included acanthosis, hyperkeratosis and subacute inflammation in all sites. Epidermal exudate was also observed. These findings are considered to be compound-related and indicate mild dermal irritation.

Any other information on results incl. tables

Based on the primary irritation score of 6.2, this test material is considered to be a severe skin irritant. Compound-related microscopic observations occurred at all treated sites.

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on a primary irritation score of 6.2, the test material is considered to be a severe skin irritant. There were compound-related microscopic observations at all treated sites.
The mean value of the scores for erythema and edema formation for 24, 48 and 72 hours was calculated to be 3.5 and so will be classified as irritating according to the dangerous substances directive, 67/548/EEC.

Executive summary:

One-half milliliter of the test material was applied to two intact and two abraded areas on the back of each of six rabbits for four hours. The primary irritation score was 6.2. Erythema and edema were observed one hour after unwrapping. Severe erythema vas observed at 24 hours and persisted in some cases through Day 14; edema was present through Day 7.

Other signs of severe skin irritation were also observed; there were no significant differences between intact and abraded sites. Compound-related microscopic findings included acanthosis, hyperkeratosis and subacute inflammation in all sites. Epidermal exudate was also observed.

Based on a primary irritation score of 6.2, the test material is considered to be a severe skin irritant. There were compound-related microscopic observations at all treated sites. The mean value of the scores for erythema and edema formation for 24, 48 and 72 hours was calculated to be 3.5 and so will be classified as irritating according to the dangerous substances directive, 67/548/EEC.