Trisodium bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-4-hydroxy-5-nitrobenzenesulphonato(3-)]chromate(3-)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

other: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Test procedures cannot be subsumed under testing guideline today commonly used in the ambit of the REACH Regulation, nevertheless they followed other internationally accepted guideline, are well documented and scientifically acceptable. Justification for Read Across is detailed in the endpoint summary.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1975

Report date:

1975

Materials and methods

Principles of method if other than guideline:

The procedure adopted was the patch-test technique described in the "Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics" (1959) of the US Association of Food and Drug Officials (AFDO).

GLP compliance:

no

Remarks:

pre GLP

Test material

Test material information

Constituent 1

Reference substance name:

Similar Substance 01 (AR357)

IUPAC Name:

Similar Substance 01 (AR357)

Test animals

Species:

rabbit

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Bred: rabbits of the Russian breed.
- Weight at study initiation: 1.5 to 2 kg
- Housing: in order to prevent injuries by bites the rabbits were kept separately in V2A wire cages.
- Diet: ad libitum, standard rabbit food - NAFAG, Gossau SG, rabbit food.
- Water: ad libitum.

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

other: polyethylene glycol (PEG 400)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 g

VEHICLE
- Concentration: before application a 50 % polyethylene glycol trituration (PEG 400) was made.

Duration of treatment / exposure:

24 hours

Number of animals:

3 males and 3 females

Details on study design:

TEST SITE
- Area of exposure: rabbits were shaved on the whole back and flanks two days before treatment with an electric clipper. The shaven skin on the left side was slightly scarified immediately before treatment.
- Application: a gauze patch 2.5 x 2.5 cm was soaked with the test substance and immediately applied to the prepared skin..
- Type of wrap if used: the patch was covered with a plastic film 5 x 5 cm, which was fixed to the body with adhesive tape.

SCORING SYSTEM
The reaction of the skin was appraised upon removal and 72 hours after it. The primary irritation index as the measure of the acute skin irritation provoked by the test substance is defined as the average of all the ratings found after 24 and 72 h on the intact and slightly scarified skin.
Compounds producing combined averages (primary irritation indexes) of 2 or less are only mildly irritating; whereas those with indexes from 2 to 5 are moderate irritants, and those with scores above 6 are considered severe irritants.

Score for skin irritation in rabbits:
Erythema and Eschar Formation
No erythema: 0
Very slight erythema (barely perceptible): 1
Well defined erythema: 2
Moderate to severe erythema: 3
Severe erythema (beef redness) to slight eschar formation (injuries in depth): 4
Maximum possible: 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 mm): 3
Severe oedema (raised more than 1 mm and extending beyond area of exposure): 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: all tested animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: No dermal effects observed

Results 2

Irritation parameter:

edema score

Basis:

animal: All tested animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: No dermal effects observed

Irritant / corrosive response data:

The primary irritation index as the measure of the acute irritation to the skin of rabbits was found to be 0.

Any other information on results incl. tables

Evaluation of the skin reaction

Animal No. (sex)	Skin Reaction	24 h after application		72 h after application
		Intact skin	Abraded skin	Intact skin	Abraded skin
1 M	Erythema	0	0	0	0
	Oedema	0	0	0	0
2 M	Erythema	0	0	0	0
	Oedema	0	0	0	0
3 M	Erythema	0	0	0	0
	Oedema	0	0	0	0
4 F	Erythema	0	0	0	0
	Oedema	0	0	0	0
5 F	Erythema	0	0	0	0
	Oedema	0	0	0	0
6 F	Erythema	0	0	0	0
	Oedema	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information according to the CLP Regulation Criteria used for interpretation of results: EU

Conclusions:

Not irritating.

Executive summary:

Method

The purpose of this test was to determine the primary-irritation index, which serves as a measure of the acute irritation, provoked by the compound on the skin of the rabbits. The procedure adopted was the patch-test technique described in the "Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics" (1959) of the US Association of Food and Drug Officials (AFDO). Before treatment the whole back and the flank of the rabbits were shaved and immediately before treatment the shaven skin on the left side was slightly scarified. A gauze patch of 2.5 x 2.5 cm was soaked with the test substance (0.5 in 50 % PEG) and it was applied to the prepared abraded and intact skin. The patches were covered with a plastic film, which was fixed to the body with adhesive tape. The dressings were removed after a 24 hour exposure and the reaction of the skin was appraised upon removal and 72 hours after it.

Results

The primary irritation index as the measure of the acute irritation to the skin of rabbits was found to be 0.

Conclusion

The scoring system criteria used to record the hardness of the skin reactions followed in the current test are the same as those reported into the OECD guideline, therefore it is possible to re-evaluate the results, because the raw tables are included into the study report.

Despite the reaction scores at 48 hours were not reported, the mean value scored is reasonably expected to be less than 2.3 for erythema/eschar and for oedema in at least 2 of 3 tested animals from gradings at 24, 48 and 72 hours after patch removal, in both the cases of intact and abraded skin.

In conclusion, it is reasonable to state that the substance does not meet the criteria to be classified as skin irritant, according to the CLP Regulation (EC 1272/2008).