3-hydroxy-N-(o-tolyl)-4-[(2,4,5-trichlorophenyl)azo]naphthalene-2-carboxamide

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Skin sensitizing potential of Pigment Red 112 (containing <0.01% Naphtol AS-D) was tested in a Local Lymph Node Assay (LLNA) according to OECD test guideline 429 (RCC, 2008). In this assay selected as key study S.I. values of 1.16, 1.15 and 0.68 were determined with the test item at concentrations of 0.5%, 10% and 20% in DMSO.

From the production process, Naphtol AS-D (EC No. 205-205-0, CAS No. 135-61-5) may be present as an impurity in Pigment Red 112. Naphtol AS-D is a skin sensitizer. According to directive 1999/45/EC and regulation EC/1272/2008 a substance has to be classified as a skin sensitizer when the concentration of a sensitizing impurity is >= 1%.

 

In an LLNA in which the test item Pigment-Komposition 112/ASD (Pigment Red 112) contained 4.1% Naphtol AS-D, the test item was found to be a skin sensitizer in the LLNA when tested at up to 20% in acetone/olive oil 4:1 (v/v). S.I. values of 3.3, 4.7 and 3.9 were obtained for tested concentrations of 5%, 10% and 20%. The test result supports the view that the sensitizing impurity Naphtol AS-D can render the substance Pigment Red 112 positive in a skin sensitization assay when present at sufficiently high concentrations.

 

In another skin sensitization test, the test item Pigment Composition 112/ASD (Pigment Red 112), containing 3% Naphtol AS-D, was tested in an OECD guideline and GLP compliant skin sensitization test (Buehler test) in guinea pigs. The test item did not cause signs of skin sensitization in this test. This result supports the view that the substance Pigment Red 112 is not skin sensitizing when the concentration of the sensitizing impurity Naphtol AS-D is sufficiently low. Since a Naphtol AS-D concentration of 3% in Pigment Red 112 did not result in sensitizing effects, the generic concentration limit of is >= 1% according to directive 1999/45/EC and regulation EC/1272/2008 is considered adequate to distinguish Pigment Red 112 with Naphtol AS-D concentration >= 1% that has to be classified as skin sensitizing, and Pigment Red 112 with Naphtol AS-D concentration < 1% that does not require classification.

Migrated from Short description of key information:
In an OECD guideline and GLP compliant LLNA (RCC, 2008), Pigment Red 112 (containing <0.01% Naphtol AS-D) was found to be not a skin sensitiser when tested at 0, 0.5, 10 and 20% in DMSO.

The test item Pigment-Komposition 112/ASD (Pigment Red 112 containing 4.1% Naphtol AS-D) was found to be a skin sensitiser in the LLNA (RCC, 2002) when tested at 0, 5, 10 and 20% in acetone/olive oil 4:1 (v/v). The EC3 value could not be calculated, since no dose-response relation could be observed and all SI values were above 3.

In an OECD guideline and GLP compliant skin sensitization test (Buehler test) in guinea pigs (ProTox, 2002), Pigment Composition 112/ASD (Pigment Red 112 containing 3% Naphtol AS-D) did not cause signs of skin sensitization using a concentration of 20% in sesame oil for induction and challenge.

Respiratory sensitisation

Endpoint conclusion

Additional information:

Migrated from Short description of key information:
Respiratory tract sensitisation:
Substance is not classified for this endpoint. The substance is considered not to exert any sensitizing effects on the respiratory tract, when it is not classifiable as skin sensitizing. When aerosolized in respirable form, the substance is considered likely to behave like an inert dust.
Non-human information: This information is not available.

Justification for classification or non-classification

As discussed above, the requirement to classify Pigment Red 112 depends on its concentration of the sensitizing impurity Naphtol AS-D (EC No. 205-205-0, CAS No. 135-61-5).

 

Pigment Red 112 containing Naphthol AS-D at < 1% does not have to be classified as a skin sensitizer according to the criteria laid down in the EU Dangerous Substances Directive (67/548/EEC) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC).

 

Pigment Red 112 containing Naphthol AS-D at >= 1% has to be labeled

- according to the EU Dangerous Substances Directive (67/548/EEC) as skin sensitizer, indication of danger: irritant, symbol Xi, risk phrase: R43 May cause sensitisation by skin contact

- according to the EU Classification Labelling and Packaging Regulation (1272/2008/EC) as Skin sensitisation – Category 1, Signal Word: Warning, Hazard Statement: H317: May cause an allergic skin reaction