3-methyl-2-[(1-methyl-2-phenyl-1H-indol-3-yl)azo]thiazolium chloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979-02-15 to 1979-03-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Principles of method if other than guideline:

Following a method from "Code Federal Regulations" Title 16, Sections 1500, 41 and 42

GLP compliance:

no

Test material

Test material information

1

Reference substance name:

3-methyl-2-[(1-methyl-2-phenyl-1H-indol-3-yl)azo]thiazolium chloride

EC Number:

255-785-4

EC Name:

3-methyl-2-[(1-methyl-2-phenyl-1H-indol-3-yl)azo]thiazolium chloride

Cas Number:

42373-04-6

Molecular formula:

C19H17N4S.Cl

IUPAC Name:

3-methyl-2-[(1-methyl-2-phenyl-1H-indol-3-yl)azo]thiazolium chloride

Test material form:

solid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.5 – 3.5 kg (males)
- Housing: The rabbits were kept in individual cages measuring 540 x 360 x 315 mm or in restraining devices which allow the back of the animal to be treated.
- Diet (e.g. ad libitum): ad libitum, 200 g of food is provided per animal per day in the form of granules (Granulés Lapin “entretien” SANDERS)
- Water (e.g. ad libitum): ad libitum
Animals were vaccinated against pasteurellosis and myxornatosis.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2 °C
- Humidity (%): 55 ± 20%
- Air changes (per hr): 12

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g, moistend with water (0.4 mL)

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.4 mL

Duration of treatment / exposure:

24 hours

Observation period:

7 days

Number of animals:

3 males

Details on study design:

TEST SITE
- Area of exposure: left flank (intact skin), right flank (scarified skin)
- % coverage: 2 x 2 cm
- Type of wrap if used: The treated areas are covered with a 2 cm square gauze pad consisting of sterile, hydrophilic gauze of four layers. The test material and the gauze pads are kept in contact with the skin by a occlusive patch (Neodermotest Roc) consisting of a central, circular disc of 22 mm diameter with a surrounding adhesive, hypoallergenic, perforated plaster 10 mm wide. Occlusive patches are used to keep the product in contact with the skin since they increase the hydration of the skin and the permeability of the stratum corneum. Finally, an adhesive tape 6 cm is wound around the animal to complete the fixing of patches.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, after 24 hours surplus material which had not penetrated through the skin was removed with a sterile gauze pad soaked in warm water.

OBSERVATION TIME POINTS
1h and 48 hours after patch removal. If after the last reading, any irritation is noted, the animals are maintained under observation for one week. After a total of 7 days, another reading is made.
SCORING SYSTEM:
- Method of calculation: Draize (see Table 1 in box "Any other information on materials & methods incl. tables")

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 3 animals

Time point:

24/48/72 h

Max. score:

4

Remarks on result:

not determinable

Remarks:

Erythema could not be assessed as the skin was stained red by the test material

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 3 animals

Time point:

7 d

Score:

0

Max. score:

4

Results 3

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No irritation effects were observed on intact skin. Examination of the erythema was mainly impossible within the first 72 h due to the colouration of the skin by the test item. For individual results on intact skin please refer to Table 2 in box "Any other information on results incl. tables".

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this acute dermal irritation/corrosion study, the test item can be considered as non-irritating to the skin.

Executive summary:

In a primary dermal irritation study, three male New Zealand White rabbits were dermally exposed to 0.5 g of the test item for 24 hours to a body surface area of 2.0 x 2.0 cm under occlusive conditions. Irritation was scored by the method of Draize at 1, 48 hours and 6 days after patch removal. No signs of irritation have been recorded at any of the observation time points. Based on the results, the test item can be considered as not dermally irritating.