Sodium 2,4-diamino-5-(2-hydroxy-5-nitrophenylazo)benzenesulphonate

Endpoint summary

Description of key information

Skin sensitising

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The potential of the test item to cause skin sensitisation reactions following topical application to the skin of CBA/JN mice, was assessed using the LLNA:BrdU-ELISA method, according to the OECD Guideline for testing of chemicals No. 442b.

According to the results of the irritation screening, the concentration of 25% w/w was judged to be not irritant. In the main assay, the test item was topically administered at the concentrations of 25, 10 and 5% (w/w), in acetone:olive oil 4:1 (v/v).

No mortality nor clinical signswere recorded in any animal. Changes in bodyweight observed during the study were within the expected range for this strain and age of animals.

The calculated Stimulation Indices (SI) were 0.89, 1.69 and 2.20, respectively at the low, mid- and high dose levels [5, 10 and 25 %, respectively].

An increase in cell proliferation of draining lymph nodes, statistically significant and correlated with the dose was observed in mid- and high dose group. The results indicate that the test item may elicit a sensitisation response in mice following dermal exposure, since in mid- and high dose groups the Stimulation Index was greater than 1.6.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin sensitisation

According to the CLP Regulation n. 1272/2008, substances shall be classified as skin sensitisers (Category 1) where data are not sufficient for sub- categorisation (1A and 1B) 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 (according to 3.4.2.2.4.1).

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.

The calculated Stimulation Indices (SI) were 0.89, 1.69 and 2.20, respectively at the low, mid- and high dose levels [5, 10 and 25 %, respectively].

The results indicate that the test item may elicit a sensitisation response in mice following dermal exposure, since in mid- and high dose groups the Stimulation Index was greater than 1.6. Since the SI results indicate a value < 2 and > 2 it is not possible define a category (1A or 1B).

As conclusion, according to the paragraph 3.4 of the CLP Regulation n. 1272/2008, table 3.4.3, the registered substance is classified as skin sensitizer, H317 May cause an allergic skin reaction.