2,4-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 -18, 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study has been performed according to OECD and/or EC guidelines 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:

2,4-bis[N'-(4-methylphenyl)ureido]toluene

EC Number:

411-790-5

EC Name:

2,4-bis[N'-(4-methylphenyl)ureido]toluene

Cas Number:

54390-87-3

Molecular formula:

C23H24N4O2, C24H34N4O2

IUPAC Name:

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

Details on test material:

- Name of test material (as cited in study report): KY-MA
- Physical state: Light yellow solid

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: 13-16 weeks
- Weight at study initiation: 2680-2699 grams
- Housing: Animals were housed individually in cages with perforated floors.
- Diet: Free access to standard laboratory diet (LKK-20, pellet diameter 4mm, Hope Farms, Woerden, The Netherlands)
- Water: Free access to tap water.
- Acclimation period: At least 5 days

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:

shaved

Vehicle:

other: The test substance was moistened with distilled water.

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 test substance was moistened with distilled water.

Duration of treatment / exposure:

Single application.

Observation period:

4 days.

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 patchmounted on Micropore tape. The dressing was wrapped around the abdomen and secured with an elastic bandage.

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 of animals #2 and #3 also on day 4.

The test substance was applied to the skin of one flank, using a patch of 2x3 cm. However, due to the low density in animal #1 some of the test substance was applied outside the application area of 2x3 cm (total area 3x4 cm).

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 55 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:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

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 3

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 4

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 5

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 6

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

Irritant / corrosive response data:

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

Other effects:

There was no evidence of a corrosive effect on the skin and 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.

Applicant's summary and conclusion

Interpretation of results:

other: not irritating

Remarks:

according to Regulation (EC) No 1272/2008 and its amendments

Conclusions:

In an skin irritation study with rabbits, performed according to OECD 404 (1981) and EC B.4 (1984) test guidelines, no irritation was observed.

Executive summary:

KY-MA 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-MA 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-MA was observed. No signs of systemic intoxication were observed during the study period. Based on these results, KY-MA 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.