Reaction mass of sodium 3-[[4-[(4-ethoxy-m-tolyl)azo]-1-naphthyl]azo]benzenesulphonate and sodium 3-[[4-[(4-ethoxyphenyl)azo]-1-naphthyl]azo]benzenesulphonate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

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:

The test was carried out according to the method given in the "Hazardous Substances Regulations" under the U.S. Federal Hazardous Substances Labelling Act Sect. 191.11 (February 1965).

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Similar Substance 02

IUPAC Name:

Similar Substance 02

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 - 13 weeks.
- Weight at study initiation: average 2.05 kg males and 2.22 kg females.
- Housing: rabbits were caged singly.
- Diet: commercial irradiated diet (Styles-Oxoid), ad libitum.
- Water: sterile filtered water, ad libitum.
- Acclimation period: one week prior to the start of the trial.

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 1 °C
- Relative humidity: 50 - 70 %
- Photoperiod: animals were exposed to artificial light for 10 hours daily from 08.00 - 18.00 hours.

Test system

Type of coverage:

occlusive

Preparation of test site:

other: shaved and abraded

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

Amount: 0.5 g
Fromulaiton: 10 g.of the test compound was mixed with 10 ml of water to make a solution of 15 ml, 0.75 ml of which was applied to each test site on a 2.5 cm square gauze pad.

Duration of treatment / exposure:

24 hours

Observation period:

72 hours

Number of animals:

3 males and 3 females

Details on study design:

TEST SITE
- Area of exposure: 24 hours prior to the dermal application, the backs of the rabbits were shaved. Two test sites lateral to the mid line of the back were used on each rabbit. Immediately before the application of the test compound, the right hand site was abraded uith the point of a sterile hypodermic needle. The abrasions were sufficiently deep to penetrate the stratum corneum but not to damage the dermis.
- % coverage: at least 10 % of the total body surface.
- Type of wrap if used: animals were covered with aluminium foil secured with "Sleek" adhesive tape. The test sites were then enclosed by a 6 wide "Coban" self adhesive bandage the edges of which were fixed to the skin by strips of "Sleek" in order to retain the test substance in close contact with the skin.

OBSERVATION TIME POINTS
After 24 hours the dressing was removed and the intact and abraded application sites were assessed for oedema and erythema. A further assessment wes made at 72 hours.

SCORING SYSTEM

Erythema and Eschar Formation
No erythema 0
Slight erythema (barely perceptible) 1
Well defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet red) to slight eschar formation 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 the area of exposure) 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 6/6

Remarks:

both intact and abraded

Time point:

24/48/72 h

Score:

< 2.3

Reversibility:

fully reversible within: 72 hours

Results 2

Irritation parameter:

edema score

Basis:

animal: 6/6

Remarks:

both intact and abraded

Time point:

24/48/72 h

Score:

< 2.3

Irritant / corrosive response data:

A slight to well defined erythema and a very slight to slight oedema was seen in all rabbits 24 hours after application of the compound. A very slight oedema was still present in 3/6 rabbits at 72 hours. Also at this time 3/6 (No. 11, 14, 15) rabbits were showing slight desquamation of the epidermis at the application sites.
There was no significant difference between intact and abraded sites.
The primary irritation score was 1.6.

Any other information on results incl. tables

Animal N.	Reaction	Itact skin		Itact skin
		24 hrs	72 hrs	24 hrs	72 hrs
11 male	Erythema	1	0	1	0
13 male		1	0	1	0
15 male		1	0	1	0
12 female		1	0	1	0
14 female		2	0	2	0
16 female		1	0	1	0
11 male	Oedema	2	0	1	0
13 male		2	0	2	1
15 male		2	1	1	1
12 female		2	0	1	0
14 female		2	0	2	0
16 female		1	1	2	1

Applicant's summary and conclusion

Interpretation of results:

other: not classified, according to the CLP Regulation (EC) No 1272/2008

Conclusions:

Mild irritating

Executive summary:

The skin irritation potential of test item was assessed in six New Zealand White rabbits. The test was carried out according to the method given in the "Hazardous Substances Regulations" under the U.S. Federal Hazardous Substances Labelling Act Sect. 191.11 (February 1965).

A slight to well defined erythema and a very slight to slight oedema was seen in all rabbits 24 hours after application of the compound. A very slight oedema was still present in 3/6 rabbits at 72 hours. Also at this time 3/6 (No. 11, 14, 15) rabbits were showing slight desquamation of the epidermis at the application sites.

There was no significant difference between intact and abraded sites.

The primary irritation score was 1.6.

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 in accordance with the CLP Regulation (EC) No 1272/2008. Althought the observation time points were 24 and 72 hours, the mean scores for grading at 24, 48 and 72 hours can be reasonably estimated.

The mean values from gradings at 24, 48 and 72 hours were lower than lower than 2.3 for both erythema and oedema, in all the tested animals, both with skin shaved and scarified. Therefore, the substance does not meet the criteria to be classified as eye irritating, according to the CLP Regulation (EC) No 1272/2008.