1,2,4-trimethylbenzene

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study, GLP status unclear, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Evaluation of the test method for skin irritation as prescribed by OECD and EEC

Author:

Jacobs G and Martens M

Year:

1987

Bibliographic source:

J Toxicol Cutaneous Ocul Toxicol V6 pp215-226

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Principles of method if other than guideline:

Mesitylene was applied to shaved rabbit skin and erythema and oedema recorded (using Draize criteria) at 1, 24, 48, and 72 hr after removal of the patch. Observations continued thereafter every 2 days until dermal responses had resolved in at least one rabbit.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Mesitylene

EC Number:

203-604-4

EC Name:

Mesitylene

Cas Number:

108-67-8

Molecular formula:

C9H12

IUPAC Name:

1,3,5-trimethylbenzene

Constituent 2

Reference substance name:

1,3,5-trimethylbenzene

IUPAC Name:

1,3,5-trimethylbenzene

Details on test material:

- Name of test material (as cited in study report): mesitylene
- Lot/batch No.: M720-0
- Supplier: Janssen Chimica, Beerse, Belgium
- Purity: no further details

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Proefstations voor Veeteelt (Merelbeke, Belgium)
- Age at study initiation: 9-24 weeks
- Weight at study initiation: 2.75-5.2 kg
- Housing: individual mesh wire bottom cages
- Conventional Laboratory diet ad libitum
- Tap-water ad libitum
- Acclimation period: At least 7 days
- Normal housing conditions

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: area of untreated skin used for comparison

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

4 hours, occluded

Observation period:

The animals were examined for signs of erythema and oedema formation at 1, 24, 48 and 72 hr after removal of the test patch

Number of animals:

5 or 6 (not specified)

Results and discussion

In vivo

Results

Irritation parameter:

erythema score

Basis:

other: mean for all animals, all timepoints

Time point:

other: overall mean for 24, 48 and 72 hr

Score:

2.33

Remarks on result:

other: time course information not available

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Mesitylene caused erythema (overall mean 2.33) when applied to shaved rabbit skin under occlusion for 4 hr

Executive summary:

The skin irritation potential of mesitylene toward shaved rabbit skin was evaluated according to Annex V of directive 67/548 EEC. The sample (0.5 mL) was applied under occlusion for 4 hr with an area of untreated skin serving as control. The overall mean score for erythema (all animals over a 72 hour period) was 2.33; no oedema was reported. The results indicate that mesitylene is irritating to rabbit skin.