Tetrasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[(2-methyl-4-sulphonatophenyl)azo]naphthalene-2-sulphonate]

Endpoint summary

Description of key information

Not skin sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

The read across approach is detailed into the document attached to the IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Test performed in 1989.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Kleintierfarm Madoerin AG, CH-4414 Füllinsdorf, Switzerland.
- Age at study initiation: males 7 weeks, females 8 weeks.
- Weight at study initiation: males 353 - 586 g, females 333 - 390 g
- Housing: individually in Makrolon type-3 cages with standard softwood bedding (Lignocel, Schill AG, 4132 Muttenz, Switzerland).
- Diet: Pelleted standard Kliba 342, Batch 50/89 and 51/89 guinea pig breeding/maintenance diet ("Kliba", Klingentalmühle AG), ad libitum.
- Water: tap water ad libitum.
- Acclimation period: one week.

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 40-70 %
- Air changes: 10-15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light

Route:

intradermal

Vehicle:

water

Concentration / amount:

3 %

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

5 %

Day(s)/duration:

48 hours

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

3 %

Day(s)/duration:

24 hours

No. of animals per dose:

- Control group: 5 males + 5 females
- Test group: 10 males + 10 females

Details on study design:

RANGE FINDING TESTS
- Intradermal injections: intradermal injections (0.1 ml/site) were made into the clipped flank of two guinea-pigs at concentrations of 1, 3 and 5 % of the test article in distilled water. The resulting dermal reactions were assessed 24 hours later.
- Epidermal applications: patches of filter paper (2 cm × 2 cm) were saturated with concentrations of 3, 5, 10 and 25 % of the test article in petrolatum oil and applied to the clipped and shaved flanks of each of four guinea-pigs. The patches were covered by a strip of aluminum foil and firmly secured by elastic plaster wound round the trunk and covered with impervious adhesive tape. This procedure ensured the intensive contact of the test article with the guinea pig skin. The dressings were removed after an exposure period of 24 hours and the reaction sites were assessed for erythema and edema on a numerical basis according to Draize. Further examination of the sites was performed 24 and 48 hours after removal of the dressings. The allocation of the different test sites on the animals were alternated in order to minimize site to site variation in responsiveness.

MAIN STUDY
A. INDUCTION EXPOSURE
- Intradermal injections: an area of dorsal skin from the scapular region (approximately 6 cm × 8 cm) was clipped free of hair. Three pairs of intradermal injections (0.1 ml/site) were made at the border of a 4 cm × 6 cm area in the clipped region as follows:
1) Freund's complete adjuvant 50:50 with distilled water.
2) The test article, diluted to 3 % with distilled water.
3) The test article at the concentration used in (2), emulsified in a 50:50 mixture of Freund's complete adjuvant, and the vehicle used in (2).
- Control group: The control group was treated accordingly with the omission of the test article.

- Epidermal applications: one week after the injections, the scapular area (approximately 6 cm × 8 cm) was again clipped and shaved free of hair. A 2 cm × 4 cm patch of filter paper was saturated with the test article (5 % in petrolatum oil) and placed over the injection sites of the test animals. The patch was covered by aluminum foil and firmly secured by an elastic plastic wound round the trunk of the animal and secured with impervious adhesive tape. The dressings were left in place for approximately 48 hours. The epidermal application procedure described ensured intensive contact of test article with the guinea pig skin. The guinea-pigs of the control group were treated as described above with the omission of test article. The reaction sites were assessed for erythema and edema immediately, 24 and 48 hours after removal of the dressing, using the numerical grading system according to Draize.

B. CHALLENGE EXPOSURE


OBSERVATIONS
In addition to the sensitizing reactions, the following observations and data were recorded during test and observation period:
- Mortality/viability: once daily
- Body weights: at acclimatization start, start of application, and end of the test
- Local and systemic symptoms: daily

Challenge controls:

Treatment of the control group with test substance formulation

Positive control substance(s):

yes

Remarks:

1-chloro-2,4-dinitro-benzol

Positive control results:

A control group (dinitro-chloro-benzene) is tested twice a year in the testing laboratory for sensitivity check of the guinea pig strain. The most recent test was run during September 1988. In 6 out of 9 animals tested in this study sensitisation was observed.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

3 % in petrolatum oil

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

3 % in petrolatum oil

No. with + reactions:

0

Total no. in group:

20

Group:

positive control

Remarks on result:

positive indication of skin sensitisation

PRETEST

- Intradermal injection: according to Magnusson - Kligman and to the findings observed, the concentration selected for the main study was 3 %. The application area was red discolored and therefore a possible erythema could not be observed. Edema was observed at all concentrations.

- Epidermal application: no edema was observed, but erythema was observed in all four animals immediately after after removal of the bandage. After 24 hours in 3/4, 2/4, 1/4 and 0/4 animals exposed to 25, 10, 5, and 3 % test substance, respectively, erythema was observed. After 48 hours only in 2 out of 4 animals of the 25 % dose group erythema was observed. According to Magnusson - Kligman, and to the findings observed, the concentration selected for the induction period was 5 % and for the challenge procedure 3 %. Prior to observation the skin of all animals was depilated to facilitate the observation of a possible erythema.

 

MAIN TEST

- The highest non-irritating concentration was 3 %. No systemic toxic symptoms were evident in the guinea pigs of either the control or test group. No death occurred. The body weight gain of all animals was not affected during the test.

- Control group local effects: the application area around the injection site 1 was found to show erythema and edema from day 2 to 7. Necroses were observed at day 8 and day 10 to 18. Exfoliation was observed from day 19 to 25 (termination of test). The application area around the injection site 3 was found to show erythema and edema from day 2 to 7. Necroses were observed on day 8 and from day 10 to 16. Exfoliation was observed from day 17 to 25 (temination of test). Additionally discoloration was observed from day 23 to 25 at the first challenge application.

- Test group local effects: the application area around the injection site 1 was found to show erythema from day 2 to 7 and edema on day 2 and 3. Necroses were observed at day 8 and days 10 to 18. Exfoliation was observed from day 19 to 25 (termination of test). The application areas around the injection sites 2 and 3 were found to show edema from day 2 to 7 and discoloration was observed from day 2 to 8 and from day 10 to 16. Necroses were found on day 8 and from day 10 to 16. Exfoliation was observed from day 17 to 25 (termination of test). Additionally discoloration was observed from day 10 to 16 after the epidermal application and from day 22 to 25 at the first challenge application. On day 9 of the test no observation could be performed because the animals were treated semi occlusively.

Interpretation of results:

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

Conclusions:

Not skin sensitizing

Executive summary:

The skin sensitisation potential of the test item was tested in a Guinea Pig Maximization Test with a group of 10 male and female Dunkin-Hartley guinea pigs. Induction was performed by intradermal injection at 3 % in water and topical application at 5 % in petrolatum oil. The test and control guinea-pigs were challenged two weeks after the epidermal induction application. Two patches of filter paper were saturated with non-irritant concentration (3 % in petrolatum oil) of the test article and with the vehicle only. The dressings were removed approximately 24 hours later. The sites were assessed for erythema and edema immediately, 24 and 48 hours after removal of the dressing, using the numerical scoring system according to Draize. No systemic toxic symptoms were evident in the guinea pigs of either the control or test group. No death occurred. The body weight gain of all animals was not affected during the test.

No reaction were recorded into the treated groups at the 24 and 48 hours readings.

Conclusion

Not skin sensitizing

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There are no information about the skin sensitization potential of Direct Orange 118, thus the available data on structural analogue Similar Substance 02 was taken into consideration. The read across approach can be considered as reliable and suitable for the purpose; details are available in IUCLID section 13.

The skin sensitisation potential of Similar Substance 02 was tested in a Guinea Pig Maximization Test with a group of 10 male and female Dunkin-Hartley guinea pigs. No systemic toxic symptoms were evident in the guinea pigs of either control or test group. No death occurred; the body weight gain of all animals was not affected during the test. No reaction were recorded into the treated groups at the 24 and 48 hours readings (Research & Consulting Company AG, 1989).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

According to the CLP Regulation (EC) No 1272/2008, 3.4 Respiratory or skin sensitisation section, skin sensitizer means a substance that will lead to an allergic response following skin contact.

A substance is considered a skin sensitizer when a non-adjuvant Guinea pig test method a response of at least 15 % of the animals is considered positive.

In the experiment available, performed on the Similar Substance 02, less than the 30 % of animals showed a reaction in the Guinea Pig Maximisation Test.

In conclusion, the substance does not meet the criteria to be classified as skin sensitizer, according to the CLP Regulation (EC) No 1272/2008.