3,3'-[[4-[(2-chloro-4-nitrophenyl)azo]phenyl]imino]bis[propiononitrile]

Endpoint summary

Description of key information

Sensitising

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The skin sensitisation of the test substance has been evaluated using a Buheler test, according to the OECD Guidelines 406.

Twenty female animals of the test group were treated topically with the test substance at 50% in bi-distilled water once a week for a 3 week induction phase. Two weeks after the final induction application the animals were challenged with the same test article concentration of 50% in bi-distilled water as used for induction. The ten animals of the control group were not treated during the induction but were treated once at challenge with the test substance at 50% in bi-distilled water.

In this study 40% of the animals of the test group were observed with skin reactions after challenge treatment performed with the highest non-irritating concentration of the test substance at 50% in bi-distilled water. No skin reactions were observed in the control group treated in the same conditions during the challenge phase.

This result is in line with the one achieved with other tests listed in the table attached below.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

SKIN SENSITIZATION

Category 1

Substances shall be classified as skin sensitizers in category 1 where data are not sufficient for sub-categorisation in accordance with the following criteria:

(a) If there is evidence in humans that the substance can lead to sensitisation by skin contact in a substantial number of persons; or

(b) If there are positive results from an appropriate animal test.

Specific criteria of animal test:

When an adjuvant type test method for skin sensitisation is used, a response of at least 30% of the animals is considered as positive.

For a non-adjuvant Guinea pig test method a response of at least 15% of the animals is considered positive.

Furthermore, stimulation index of three or more is considered a positive response in the local lymph node assay.

Sub-category 1A:

Substances showing a high frequency of occurrence in humans and/or a high potency in animals can be presumed to have the potential to produce significant sensitisation in humans. Severity of reaction may also be considered.

Specific criteria:

Local lymph node assay-EC3 value ≤ 2%

Guinea pig maximisation test-≥ 30% responding at ≤ 0.1% intradermal induction dose or ≥ 60% responding at > 0.1% to ≤ 1% intradermal induction dose.

Buehler assay - ≥ 15% responding at ≤ 0.2% topical induction dose or ≥ 60% responding at > 0.2% to ≤ 20% topical induction dose

Sub-category 1B:

Substances showing a low to moderate frequency of occurrence in humans and/or a low to moderate potency in animals can be presumed to have the potential to produce sensitisation in humans. Severity of reaction may also be considered.

Local lymph node assay - EC3 value > 2%

Guinea pig maximisation test- ≥ 30% to < 60% responding at > 0.1% to ≤ 1% intradermal induction dose or ≥ 30% responding at > 1% intradermal induction dose.

Buehler assay - ≥ 15% to < 60% responding at > 0.2% to ≤ 20% topical induction dose or ≥ 15% responding at > 20% topical induction dose.

Based on animal test (Buehler assay) results performed, according to the paragraph 3.4. of the CLP Regulation n. 1272/2008, the test substance is classified in Sub Category 1B, as 40% of the animals were positive after treatment (intradermal dose = 50% of test substance).