2,4,6-trimethylphenol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Draize, J.H., "Dermal Toxicity", Appraisal of the Safety of Chemicals in Food, Drugs and Cosmetics-Dermal Toxicity, Pp.49-52. Association of Food and Drug Officials of the U.S., Topeka, Kansas, 1965.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,4,6-trimethylphenol

EC Number:

208-419-2

EC Name:

2,4,6-trimethylphenol

Cas Number:

527-60-6

Molecular formula:

C9H12O

IUPAC Name:

2,4,6-trimethylphenol

Test material form:

other: powder or cake

Details on test material:

- Name of test material (as cited in study report): 2,4,6-Trimethyl phenol (TMP, Mesitol)
- Batch #: (Grade 8093)
- Description: White crystalline powder or cake
- Physical state: Solid
- Stability: Stability under normal storage and use conditions
- Storage: Room temperature (in hood preferably)
- Color: White

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Millbrook Breeding Labs, Amherst, MA
- Age at study initiation: at least 10 weeks old (adult)
- Weight at study initiation: 2.02 – 2.06 kg
- Housing: Individual housing (Suspended stainless-steel cages); Bedding: Hardwood chips, (non-contact), Prochip, Harlan Teklad, Madison, WI
- Diet: TEK 8630 Rabbit Diet, Harlan Teklad, Madison, WI, ad libitum
- Water: Tap water, ad libitum
- Acclimation period: 5 days, under the same conditions as for the actual test

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 30-70
- Air changes (per hr): 10 to 15
- Photoperiod (hrs dark / hrs light): 12-Hour light/dark cycle, full spectrum fluorescent lights

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Remarks:

moistened

Controls:

no

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3: 2 males and 1 female

Details on study design:

TEST SITE
- Area of exposure: 6 cm2 on the trunk
- Type of wrap if used: Gauze patch, which was held in place with non-irritating tape. The patch was loosely held in contact with the skin for the duration of the exposure period.

REMOVAL OF TEST SUBSTANCE
- Time after start of exposure: 4 hours

SCORING SYSTEM:
- Animals were observed for signs of erythema and edema at 60 minutes, and then at 24, 48, and 72 hours after patch removal. Observations were scored according to the "Draize Scale for Scoring Skin Reactions
- Daily clinical observations included all toxicologic and pharmacologic signs.
- Animals were weighed at the end of the observation period

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

edema score

Basis:

animal: #1, #2, and #3

Time point:

other: mean 24, 48, and 72 hours

Score:

0

Max. score:

4

Results 2

Irritation parameter:

erythema score

Basis:

animal: #1, #2, and #3

Time point:

other: mean 24, 48, and 72 hours

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Irritant / corrosive response data:

Following a 4-hour exposure, all three rabbits exhibited very slight erythema at both the 24- and 48-hour observation periods. No signs of edema were observed in any of the rabbits at any observations points. The irritation was resolved, with no signs of erythema present at the 72-hour observation.

Other effects:

- Mortality: No mortality was observed
- Body weight: All of the test animals exhibited a gain in body weight during the study.
- No overt signs of toxicity were evident in any of the animals during the course of the study.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the test, the substance is considered to be slightly irritating to the skin.

Executive summary:

2,4,6-Trimethyl Phenol (TMP, Mesitol) was evaluated for its potential to produce skin irritation and/or corrosion in a GLP compliant OECD 404 guideline study. Three New Zealand White rabbits received a single topical application for four hours to the intact skin under semi-occlusive conditions. All three rabbits exhibited very slight erythema at both the 24- and 48-hour observation periods. The irritation was resolved, with no signs of erythema present at the 72-hour observation. No signs of edema were observed in any of the rabbits at any observations points. The test substance is considered a slight irritant.