Registration Dossier

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study, available as unpublished report, minor restrictions, fully adequate for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
, occlusive conditions used
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): 2.4.6-Trimethylbenzaldehyde
- Physical state: Colorless to faint yellow clear liquid
- Storage condition of test material: refrigerator

Test animals

Species:
rabbit
Strain:
other: Japanese White rabbits K bL:JW (SPF)
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Kitayama Labes Co., Ltd.
- Age at study initiation: ca. 10 weeks
- Weight at study initiation: 2.2-2.4 kg
- Housing: individually housed in suspended metallic cages on a Z-type rabbit cage rack washable with water (ZR-18U, Natsume Seisakusho Co., Ltd.).
- Diet: Pellet food for rabbits RC-4 (Oriental Yeast Co., Ltd.), ad libitum.
- Water: Tap water, ad libitum.
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 55 ± 6
- Photoperiod (hrs dark / hrs light):12/12

Test system

Type of coverage:
occlusive
Preparation of test site:
clipped
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 5 mL on a circle of about 6 cm2
Duration of treatment / exposure:
4 hours
Observation period:
7 days
Number of animals:
3
Details on study design:
TEST SITE
- Area of exposure: 6cm2
- Type of wrap if used: double-layer gauze and occlusively secured with Tegaderm (3M) and Tubicot No. 5 (Alcare Co., Ltd.)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Applied areas were wiped with gauze moistened with water.
- Time after start of exposure: 4 hours

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
other: mean 24, 48, and 72 hours
Score:
2.7
Max. score:
4
Reversibility:
fully reversible within: 6 days
Irritation parameter:
erythema score
Basis:
other: #2, #3
Time point:
other: mean 24, 48, and 72 hours
Score:
2.3
Max. score:
4
Reversibility:
fully reversible within: 6 days
Irritation parameter:
edema score
Basis:
animal: #1, #2, #3
Time point:
other: mean 24, 48, and 72 hours
Score:
1.7
Max. score:
4
Reversibility:
fully reversible within: 6 days
Irritant / corrosive response data:
Two rabbits showed well-defined erythema (score 2) 30-60 min after 4-hr exposure. One rabbit showed very slight (barely perceptible) erythema (score 1), while another showed very slight (barely perceptible) edema (score 1). At 24 and 48 hrs after exposure, all three rabbits showed intensified dermal changes with well defined or moderate to severe erythema (score 3) and slight edema (score 2). A tendency toward recovery was noted thereafter, with all three rabbits showing a recovery with scale-like changes by 7 days after termination of exposure.

Applicant's summary and conclusion

Interpretation of results:
irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the test conditions (OECD 404) the test substance is considered to be irritating to the skin.
Executive summary:

According to OECD guideline 404, a primary skin irritation study was conducted. The test substance was topically applied to the back skin (circular area of about 6 cm2) of 3 Japanese white rabbits for 4 hours under occlusive conditions. Two rabbits showed well-defined erythema (score 2) 30-60 min after exposure. One rabbit showed very slight (barely perceptible) erythema (score 1), while another showed very slight (barely perceptible) edema (score 1). At 24 and 48 hours after exposure, all three rabbits showed intensified dermal changes with well defined or moderate to severe erythema (score 3) and slight edema (score 2). A tendency toward recovery was noted thereafter, with all three rabbits showing a recovery with scale-like changes by 7 days after termination of exposure. Under the test conditions (OECD 404) the test substance is considered to be irritating to the skin.