1,7-Naphthalenedisulfonic acid, 4-amino-3-[(1E)-2-(2,4-disulfophenyl)diazenyl]-5-hydroxy-6-[(1E)-2-(4-nitro-2-sulfophenyl)diazenyl]-, sodium salt (1:5)

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Test substance concentrations selected for the main study were based on the results of a pre-screen test.

In the main study, three experimental groups of five female CBA/J mice were treated with test substance concentrations of 10, 25 or 50% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (Propylene glycol).

Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised and pooled for each animal.

After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of disintegrations per minute (DPM) and a stimulation index (SI) was subsequently calculated for each group.

No irritation and no signs of systemic toxicity were observed in any of the animals.

The auricular lymph nodes of the animals treated at 10% and 25% and control groups were considered normal in size. The majority of auricular lymph nodes of the animals treated at 50% were considered enlarged. No macroscopic abnormalities of the surrounding area were noted for any of the animals.

Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 2293, 3072 and 11192 DPM, respectively. The mean DPM/animal value for the vehicle control group was 627 DPM. The SI values calculated for the substance concentrations 10, 25 and 50% were 3.7, 4.9 and 17.9, respectively.

These results show that the test substance elicits a SI . 3. The EC3 value (the estimated test substance concentration that will give a SI =3) was established to be between 0 and 10%.

Based on these results:

- according to the recommendations made in the test guidelines (including all amendments), K1600 black dye would be regarded as skin sensitizer.

- according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011) (including all amendments), K1600 black dye should be classified as skin sensitizer (Category 1).

- according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments), K1600 black dye should be classified as skin sensitizer (Category 1) and labeled as H317: May cause an allergic skin reaction.

Migrated from Short description of key information:
A valid LLNA study was performed to examine the skin sensitising potential of the test substance. The test substance was determined to be classified as Skin Sens. 1 in accordance with Regulation (EC) No 1272/2008.

Justification for selection of skin sensitisation endpoint:
A valid study was performed at a GLP compliant laboratory in accordance with OECD, EU and US test guidance for the analysis of the skin sensitising potential of substances. Minor deviationis were observed but the validity of the study was not effected.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

These results show that the test substance elicits a SI ≥ 3. The EC3 value (the estimated test substance concentration that will give a SI =3) was established to be between 0 and 10%. Based on these results: - according to the recommendations made in the test guidelines (including all amendments), K1600 black dye would be regarded as skin sensitizer. - according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011) (including all amendments), K1600 black dye should be classified as skin sensitizer (Category 1). - according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments), K1600 black dye should be classified as skin sensitizer (Category 1) and labeled as H317: May cause an allergic skin reaction.