A mixture of: 2,4 -bis(N'-(4-methylphenyl)ureido)toluene; 2,6 -bis(N'-(4-methylphenyl)ureido)toluene

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 15, 1992 - September 18, 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD 404 (1981) and EU Method B.4 (1984) and according to GLP principles. Limited information available to verify the composition of the used test substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

(1981)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(1984)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

A mixture of: 2,4 -bis(N'-(4-methylphenyl)ureido)toluene; 2,6 -bis(N'-(4-methylphenyl)ureido)toluene

EC Number:

411-070-0

EC Name:

A mixture of: 2,4 -bis(N'-(4-methylphenyl)ureido)toluene; 2,6 -bis(N'-(4-methylphenyl)ureido)toluene

Molecular formula:

C23H24N4O2

IUPAC Name:

3-(2-methyl-5-{[(4-methylphenyl)carbamoyl]amino}phenyl)-1-(4-methylphenyl)urea

Details on test material:

- Name of test material (as cited in study report): KY-ET
- Appearance: Light yellow solid
- Storage condition of test material: At room temperature in the dark

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Source: Broekman Institute, Someren, The Netherlands
- Age at study initiation: Approx. 13 weeks
- Weight at study initiation: 2463 - 2532 grams
- Housing: Animals were housed individually in cages with perforated floors
- Diet: Free access to standard laboratory rabbit diet (LKK-20, pellet diameter 4 mm, Hope Farms, Woerden, The Netherlands) approx. 100 gram per day
- Water: Free access to tap water diluted with decalcified water
- Acclimation period: At least 5 days before start of treatment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): 55
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12
Fluctuations from these conditions were noted, but were considered not to have affected study integrity.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: approximately 24 hours before treatment, the dorsal fur was shaved with electric clippers, exposing an area of approximately 150 cm2 (10 x 15 cm)

Vehicle:

other: the powdery test substance was applied with the aid of a patch. The patch was moistened with distilled water, immediately before application

Controls:

other: Adjacent areas of the untreated skin of each animal served as controls.

Amount / concentration applied:

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

VEHICLE
The powdery test substance was applied with the aid of a patch. The patch was moistened with distilled water, immediately before application.

Duration of treatment / exposure:

Single application.

Observation period:

72 hours

Number of animals:

3 males.

Details on study design:

STUDY DESIGN
On test day 1, 0.5 gram of the test substance was applied to the intact skin of the shaved area on one flank, using a moistened Scotchpak-non-woven patch (2x3 cm, 3M, St.Paul, USA) mounted on Micropore tape (3M, St.Paul, USA). The contralateral flank was similarly prepared but without test substance and distilled water to act as a procedural control. The dressing was wrapped around the abdomen and secured with an elastic bandage (Coban, 3M, St. Paul, USA).

TEST SUBSTANCE PREPARATION
The powdery test substance was applied with the aid of a patch. The patch was moistened with distilled water, immediately before application, to ensure close contact of the test substance to the animals skin.

TEST SITE
Approximately 24 hours before treatment, the dorsal fur was shaved with electric clippers, exposing an area of approximately 150 square centimeters (10x15 cm). In order to facilitate scoring, the skin areas concerned of all animals were re-shaved before the observation on day 3 and day 4.

REMOVAL OF TEST SUBSTANCE
Four hours after the application, the dressing was removed and the remaining test substance removed using a tissue moistened with tap-water and subsequently a dry tissue.

OBSERVATIONS
- Mortality/Viability: Daily.
- Toxicity: Daily.
- Body Weight: Day 1 of test (application day)
- Necropsy: Not performed
- Irritation:
The skin reactions were assessed at approximately 45 minutes, 24, 48 and 72 hours after the removal of the dressings and test substance. The irritation scores and a description of all other (local) effects were recorded.

SCORING SYSTEM:
The irritation was assessed according to the numerical scoring system according to OECD 404.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

- No skin irritation was caused by the test substance after a 4 hour dermal application.

Other effects:

- No staining of the treated skin by the test substance was observed
- No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred

Any other information on results incl. tables

- There was no evidence of a corrosive effect on the skin

- In one animal, a small scratch was noted in the area of application at the 24, 48 and 72 hours reading. This was probably caused by scratching of the animal and was considered not to be related to treatment.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In a skin irritation study with rabbits, performed according to OECD 404 (1981) and EU Method B.4 (1984) and according to GLP principles, no irritation was observed.

Executive summary:

KY-ET was applied onto shaved skin of three male albino rabbits using semi-occlusive dressings for 4 hours. Under the conditions of this study, no skin irritation was caused by KY-ET and no corrosive effect occurred on the skin in any of the three rabbits. In the area of application, no staining of the treated skin by KY-ET was observed. No signs of systemic intoxication were observed during the study period. Based on these results, KY-ET does not have to be classified and has no obligatory labelling requirement for skin irritation according to Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.