1,3'-Bipyridinium, 5'-[[4-[[4-[(1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo[1,3'-bipyridinium]-5'-yl)azo]benzoyl]amino]phenyl]azo]-1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo-, salt with 2-hydroxypropanoic acid (1:2)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Remarks:

source of read across

Adequacy of study:

key study

Study period:

From 25th to 28th February, 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Similar substance 01

IUPAC Name:

Similar substance 01

Specific details on test material used for the study:

For the purpose of the study the test material was ground to a fine powder using a mortar and pestle.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: David Percival Ltd., Moston, Sandbach, Cheshire, U.K.
- Age at study initiation: at the start of the study the animals were approximately twelve to sixteen weeks old.
- Weight at study initiation: at the start of the study the animals weighed 2.64 - 2.78 kg.
- Housing: individually housed in suspended metal cages.
- Diet: Rabbit Diet, Preston Farmers Limited, New Leake, Boston, Lincolnshire, U.K., ad libitum.
- Water: drinking water, ad libitum.
- Acclimation period: minimum acclimatisation period of five days.

ENVIRONMENTAL CONDITIONS
- Temperature: 15 - 19 °C
- Humidity: 40 - 60 %
- Air changes: approximately 15 changes per hour.
- Photoperiod: the lighting was controlled by a time switch to give 12 hours light and 12 hours darkness.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

A quantity of 0.5 g of the test material moistened with 0.5 ml of distilled water.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

Three rabbits

Details on study design:

TEST SITE
- Area of exposure: approximately twenty-four hours prior to the commencement of the test, each rabbit was prepared by closely clipping the fur from the dorsal/flank areas using veterinary clippers. Only animals with a healthy intact epidermis by gross observation were selected for the study. Test material was introduced under a 2.5 cm × 2.5 cm gauze patch and placed in position on the shorn skin.
- Type of wrap if used: the patch was secured in position over the test material with a strip of surgical adhesive tape (BLENDERM: approximate size 2.5 cm × 4.0 cm). To prevent the animals from interfering with the patches the trunk of each rabbit was wrapped in an elasticated corset (TUBIGRIP).

REMOVAL OF TEST SUBSTANCE
- Washing: any residual test material was removed by gentle swabbing with cotton wool soaked in distilled water followed by diethyl ether.
- Time after start of exposure: 4 hours.

OBSERVATION TIME POINTS
Approximately one hour following removal of the patches, and 24, 48 and 72 hours later, the test sites were examined.

SCORING SYSTEM:
For evidence of primary irritation and scored according to the following scale i.e. Draize J.H. (1959) Association of Food and Drug Officials of the United States, Austin, Texas "The Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics".

Evaluation of skin reactions
Erythema and Eschar Formation
No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) to slight eschar formation (injuries in depth) 4

Oedema Formation
No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well-defined by definite raising) 2
Moderate oedema (raised approximately 1 millimetre) 3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure) 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 3/3

Time point:

24/48/72 h

Score:

< 2.3

Results 2

Irritation parameter:

edema score

Basis:

animal: 3/3

Time point:

24/48/72 h

Score:

< 2.3

Irritant / corrosive response data:

No erythema or oedema was noted at the 72-hour observation and the study was terminated.
No adverse dermal reactions were noted one hour after removal of the patches.
Very silght erythema was confined to one treatment site at the 24 and 48-hour observations. No adverse skin reactions were noted at the other two treatment sites during the study period.
Desquamation was noted at one treatment site at the 72-hour observation.

Any other information on results incl. tables

Individual daily and individual mean scores

Skin reaction	Reading (hour)	Individual scores - rabbit no.
		18	21	26
Ertythem/eschar	1	0	0	0
Ertythem/eschar	24	0	1	0
Ertythem/eschar	48	0	1	0
Ertythem/eschar	72	0	0D	0
Mean 24, 48 and 72 hrs		0.0	0.7	0.0
Oedema	1	0	0	0
Oedema	24	0	0	0
Oedema	48	0	0	0
Oedema	72	0	0	0
Mean 24, 48 and 72 hrs		0.0	0.0	0.0

D: desquamation

Applicant's summary and conclusion

Interpretation of results:

other: not classified, according to the CLP Ragulation (EC 1272/2008)

Conclusions:

Not skin irritant

Executive summary:

A study was performed to assess the irritation of the test material to the skin of the New Zealand White rabbit. The method followed OECD guideline 404. A single 4 -hour semi-occluded application (0.5 g of the test material moistened with 0.5 ml of distilled water) was administered to the intact skin of three rabbits. Skin reactions were recorded 1, 24, 48 and 72 hours after administration.

No erythema or oedema was noted at the 72-hour observation and the study was terminated. No adverse dermal reactions were noted one hour after removal of the patches. Very silght erythema was confined to one treatment site at the 24 and 48-hour observations. No adverse skin reactions were noted at the other two treatment sites during the study period. Desquamation was noted at one treatment site at the 72-hour observation.

Conclusion

Mean values from gradings at 24, 48 and 72 hours after patch removal were lower than 2.3 in all animals for both erythema/eschar and oedema reactions, thus the test item does not meet the criteria to be classified as irritating, according to the CLP Regulation (EC 1272/2008).