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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

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other: GLP compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment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:
2015
Report date:
2015

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
4-isobutyl-2-methylbenzaldehyde
Cas Number:
73206-60-7
Molecular formula:
C12H16O
IUPAC Name:
4-isobutyl-2-methylbenzaldehyde
Details on test material:
- Name of test material (as cited in study report): IBTAL
- Lot No.: 5N24
- Purity: 98.8%
- Description: Colorless transparence liquid
- Storage conditions: Stored at room temperature (actual temperature: 18.5°C to 20.5°C; permissible range: 1°C to 30°C) in a tight container (filled with nitrogen)
- Expiration date: March 31, 2015

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Kitayama Labes Co., Ltd; Kbl: NZW (SPF)
- Age at study initiation: 11 weeks
- Weight at study initiation: 2300 to 2472 g
- Housing: 1 animal per cage, in aluminum cages (W650 × D570 × H413 mm), Stainless-steel cascade rack and feeders; toys were used for improvement of animal welfare
- Diet: pellet diet (RC4, Oriental Yeast Co., Ltd.), ad libitum
- Water: well water admixed with sodium hypochlorite (free residual chlorine concentration: about 0.2 ppm), ad libitum
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 – 23.4
- Humidity (%): 48.5 – 63.8
- Air changes (per hr): 10 – 20
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:
semiocclusive
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): 0.5 mL
Duration of treatment / exposure:
- Initial test: 3 min, 60 min and 4 hours
- Confirmatory test: 4 hours
Number of animals:
- Initial test: 1
- Confirmatory test: 2
Details on study design:
TEST SITE
- Area of exposure: In the initial test three sites (2.5 cm × 2.5 cm each) were created on the shaved area. In the confirmatory test one site of the same size was created.
- Type of wrap if used: The test substance was placed on a 2.5 cm × 2.5 cm patch (lint cloth, Yamato Kojo Co., Ltd.) attached with a 5 cm × 5 cm non-woven adhesive bandage (Mesh-pore®, Nichiban Co., Ltd.) and placed on each application site. The application sites were occluded by an adhesive elastic bandage (Elastopore®, Nichiban Co., Ltd.).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Each occlusion was released and each application site was cleaned with absorbent cotton moisturized with lukewarm water.
- Time after start of exposure: Initial test: 3 minutes, 60 minutes, and 4 hours, confirmatory test: 4 hours

SCORING SYSTEM: The skin conditions of the 3 and 60 minutes application sites (initial test) at 1 hour after patch removal, and those of the 4 hours application site (all animals) at 1, 24, 48, 72 hours and 7 days after patch removal were scored based on the evaluation criteria for erythema and oedema formations to calculated the Primary Cutanous Irritation Index.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
other: primary cutaneous irritation index
Basis:
mean
Time point:
other: 1 - 48 h
Score:
1.2
Max. score:
8
Reversibility:
fully reversible within: 7 days
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
other: 24 - 72 h
Score:
1.7
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
other: 24 - 72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
other: 24 - 72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
edema score
Basis:
animal #1
Time point:
other: 24 - 72 h
Score:
0.7
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
edema score
Basis:
animal #2
Time point:
other: 24 - 72 h
Score:
0
Max. score:
4
Irritation parameter:
edema score
Basis:
animal #3
Time point:
other: 24 - 72 h
Score:
0
Max. score:
4
Irritant / corrosive response data:
The very slight erythema (erythema score 1) was observed in initial test at 3 and 60 minutes application sites at 1 hour after patch removal.
As a result of 4-hour exposure, very slight erythema (erythema score 1) was observed in all animals at 1 hour after patch removal. In addition, well defined erythema (erythema score 2) and very slight oedema (oedema score 1) were observed in one animal at 48 and 72 hours after patch removal. These reactions disappeared from all animals by 7 days after patch removal. Therefore, primary cutaneous irritation index (P.C.I.) was 1.2, and it was evaluated as “slightly irritant”.
Other effects:
No abnormal clinical signs or body weight gain was observed in any animal

Applicant's summary and conclusion

Interpretation of results:
slightly irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The primary cutaneous irritation index (P.C.I.) was determined to be 1.2, and the test substance was evaluated as “slightly irritant”.
Executive summary:

The acute dermal irritation or corrosion potential of the test substance was assessed in a GLP compliant OECD 404 guideline study. The test substance was topically applied to the back skin (2.5 cm x 2.5 cm) of three male New Zealand White rabbits for 4 hours under semi-occlusive conditions. Very slight erythema (erythema score 1) was observed in all animals at 1 hour after patch removal. In addition, well defined erythema (erythema score 2) and very slight oedema (oedema score 1) were observed in one animal at 48 and 72 hours after patch removal. These reactions disappeared from all animals by 7 days after patch removal. Therefore, primary cutaneous irritation index (P.C.I.) was 1.2, and it was evaluated as “slightly irritant”.