Disodium 4,4'-bis[(4,6-dianilino-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulphonate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guide-line 406 study "Skin Sensitization"

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes

Remarks:

RCC, Research & Consulting Company AG

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

other: Ibm:GOHI (SPF)

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL, Biological Research Laboratories Ltd. Wolferstrasse 4, CH-4414 Fullinsdorf
- Age at study initiation: 8 weeks
- Weight at study initiation: 396 - 432 g
- Housing: Individually in Makrolon type-3 cages with standard softwood bedding
- Diet: Pelleted standard Kliba 342, Batch 61/90 guinea pig breeding/ maintenance diet (Klingentalmuhle AG, CH-4303 Kaiseraugst), ad libitum.
- Water: Community tap water from Fullinsdorf, ad libitum. Once weekly additional supply of ascorbic acid (1g/l) via the drinking water.
- Acclimation period: 1 week


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

Route:

intradermal and epicutaneous

Vehicle:

other: intradermal: physiological saline, epicutaneous: 25 % in vaselinum album

Concentration / amount:

1st: Induction 1 % intracutaneous,
2nd: Induction 25 % occlusive epicutaneous,
3rd: Challenge 25 % occlusive epicutaneous.

Route:

epicutaneous, semiocclusive

Vehicle:

other: intradermal: physiological saline, epicutaneous: 25 % in vaselinum album

Concentration / amount:

1st: Induction 1 % intracutaneous,
2nd: Induction 25 % occlusive epicutaneous,
3rd: Challenge 25 % occlusive epicutaneous.

No. of animals per dose:

control group: 10
test group: 20
pretest: 6

Details on study design:

RANGE FINDING TESTS:
Intradermal injections (0.1 ml/site) were made into the clipped flank of 2 guinea pigs at 1, 3, and 5%. The resulting dermal reactions were scored 24 hours later. Patches of filter paper (2 x 2 cm) were covered with a thin layer of test material in vaselinum album at 5, 10, 15 and 25% and applied to the clipped and shaved flanks of each of 4 guinea pigs. The patches were covered with a strip of aluminum foil and firmly secured by elastic plaster wrapped around the trunk and covered with impervious adhesive tape. The dressings were removed after 24 hours and the reactions were scored immediately and 24 and 48 hours later.


MAIN STUDY
A. INDUCTION EXPOSURE
Intradermal: An area of dorsal skin from the scapular region (approximately 6 x 8 cm) was clipped free of hair. Three pairs of intradermal injections (0.1 ml/site) were made at the border of a 4 x 6 cm area in the clipped region. Test animals were injected with Freund's complete adjuvant:physiological saline (50:50), 1% test material (in physiological saline) or test material diluted to 1% by emulsion in a 50:50 mixture of Freund's complete adjuvant and physiological saline at the 3 sites. Control animals were injected with Freund's complete adjuvant:physiological saline (50:50), physiological saline, or a 50:50 mixture of Freund's complete adjuvant and physiological saline.

Epidermal: On day 7 of the test (approximately 24 hours prior to epidermal application), the scapular area (approximately 6 x 8 cm) was clipped, shaved free of hair and pretreated with 10% sodium-lauryl-sulfate (SLS) in petrolatum oil, because none of the concentrations given previously in the pretest (up to 25%) caused irritation. The SLS was massaged into the skin with a glass rod without bandaging. The treatment provoked a mild inflammatory reaction. A day later, a 2 x 4 cm patch of filter paper was covered with a thin layer of the selected test material concentration (25% in vaselinum album) and placed over the injection sites of the test animals. The patch was covered by aluminum foil and firmly secured by an elastic plaster wrapped around the trunk of the animals and secured with impervious adhesive tape. The dressings were left in place for approximately 48 hours. The control group was treated similarly with the omission of the test material. Reaction sites were assessed for erythema and edema immediately, and 24 and 48 hours after removal of the dressing.


B. CHALLENGE EXPOSURE
Challenge: Test and control animals were challenged 2 weeks after the epidermal induction and application. Hair was clipped from a 5 x 5 cm area on the left and right flank of each animal. Two patches (2 x 2 cm) of filter paper were covered with a thin layer of a non-irritant concentration of test material (25% in vaselinum albumin) and with vaselinum album only, applied to the left and right flank using the same method as for the epidermal application. The dressings were removed approximately 18 hours later. The sites were assessed for erythema and edema immediately, and 24 and 48 hours after removal of the dressings. Control animals were treated similarly, omitting the test material. All animals were euthanized at the end of the test with an i.p. injection of pentobarbital (> 800 mg/kg).

Positive control substance(s):

yes

Remarks:

potassium dichromate

Statistics:

Data were analyzed using the Fisher Test.

Positive control results:

For the induction period a 10 % dilution of POTASSIUM-DICHROMATE in physiological saline and for the challenge procedure a 2.5 % dilution of POTASSIUM-DICHROMATE in physiological saline was used. According to the results observed (8/10 positive) it is considered that the known allergen POTASSIUM-DICHROMATE possess a strong skin sensitizing potential in the guinea pig strain used.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

2.5%

No. with + reactions:

8

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 2.5%. No with. + reactions: 8.0. Total no. in groups: 10.0.

No positive reactions were evident after the first challenge application, neither when treated with vaselinum album only nor when treated with a 25% test article dilution.

Intradermal injection: During the pretest, all scores for erythema and edema were 2 (well defined) at all concentrations (with the exception one animal treated with 1% that had a score of 1 [barely perceptible] for erythema). According to the findings observed, the concentration selected for the main study was 1%. Epidermal application: All concentrations tested produced erythema scores of 1 (barely perceptible) immediately after exposure, with the exception that 5 and 10% produced scores of 0 in one animal at this time. All other values were 0. Based on the findings, 25% was selected for induction and challenge.

 

Main study:

Induction: All ten control animals had erythema scores of 1 (barely perceptible) immediately after removal of the bandage. One had an edema score of 1 immediately after removal of the bandage. This same animal had an erythema score of 1, 24 hours after removal. All other control scores were 0. Nine out of twenty test animals had erythema scores of 1 (barely perceptible) immediately after removal of the bandage. One test animal had an erythema score of 2 at this time. Seven out of 20 test animals had edema scores of 1 immediately after removal of the bandage. Six and two test animals had erythema scores of 1, 24 and 48 hours after bandage removal (respectively). One animal had an edema score of 1 at 24 and 48 hours.

 

Challenge: The material was not sensitizing. All controls challenged with the vaselinum album had erythema scores of 1 immediately after bandage removal. All other control scores were 0. Nine out of 10 controls challenged with test material (25%) in vaselinum album were 1 immediately after bandage removal. All other scores were 0. Nineteen out of 20 animals induced with test material and challenged with vaselinum album had scores of 1 immediately after bandage removal. All other scores in this group were 0. All 20 animals induced and challenged with test material had scores of 1 immediately after bandage removal. All other scores in this group were 0.

 

Other: None of the animals died. No clinical signs were observed. Body weight gain of animals was not affected by treatment.

 

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The substance is not sensitizing to skin.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Potential for skin sensitisation has been investigated for a close structural analogue (CAS 16090 -02 -1). Guinea pig maximisation assay has been performed and test results were consistently negative. No toxic symptoms were evident in the guinea pigs of the control or test group. No deaths occurred. From the results described no allergenic potency of the test article was concluded.

Therefore, it is concluded by read-across that the substance with CAS 133 -66 -4 is not sensitising to skin and has not to be classified for skin sensitisation.

Migrated from Short description of key information:
Read across to a close structural analogue
Not sensitising to skin as assessed in guina pig maximization assays (OECD 406) with a close structural analogue

Respiratory sensitisation

Endpoint conclusion

Additional information:

Migrated from Short description of key information:
No experimental data is available regarding respiratory sensitization.

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the family members are not considered to be classified for skin sensitisation under Directive 67/548/EEC, as amended for the 28th time in Directive 2001/59/EC.

 

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the family members are not considered to be classified for skin sensitisation under Regulation (EC) No. 1272/2008.