Registration Dossier

Administrative data

Description of key information

Not sensitising to skin as assessed in guinea pig maximization assays (OECD 406) and local lymph node assay (OECD 429) with 'yellow diazo condensation pigments' (CAS 68516-734 and CAS 5580-57-4).

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Potential for skin sensitisation has been investigated for two 'yellow disazo condensation pigments'. A guinea pig maximisation assay according to OECD TG 406 has been performed with CAS 68516-73-4 (Clariant, 2001). The maximization test was performed in 15 (10 test and 5 control) female albino guinea pigs. The intradermal induction of sensitisation in the test group was performed in the nuchal region with a 10% dilution of the test item in PEG 300 and in an emulsion of Freund's Complete Adjuvant (FCA) I physiological saline. The epidermal induction of sensitisation was conducted for 48 hours under occlusion with the test item at 30% in PEG 300 one week after the intradermal induction. The animals of the control group were intradermally induced with PEG 300 and FCA/physiological saline and epidermally induced with PEG 300 under occlusion. Two weeks after epidermal induction the control and test animals were challenged by epidermal application of the test item at 10% in PEG 300 and PEG 300 alone under occlusive dressing. Cutaneous reactions were evaluated at 24 and 48 hours after removal of the dressing. No toxic symptoms were evident in the guinea pigs of the control or test group. None of the control and test animals showed skin reactions after the challenge treatment at 10% (w/w) in PEG 300.

This result was confirmed by a local lymph node assay done with CAS 5580-57-4 according to OECD guideline 429 (Synthesia, 2008). In this study the contact allergenic potential of the test item was evaluated with non radioactive measuring of cell proliferation after topical application to female BALB/c mice. Six mice per group were exposed by test and control substances on the dorsum of both ears once a day during 3 consecutive days. Draining lymph nodes were taken off at 24 hours after the last application. Concentrations: positive control DNCB (dinitrochlorobenzene): 0.5% (w/v) and test item: 10%, 1%, 0.1% (w/v) in DAE 433. Endpoints: ear weight, auricular (ear-draining) lymph node weights and cell counts = lymph node (LN) hyperplasia. The animals exposed to the test substance at the highest concentration showed skin reactions (congestion of vessels) throughout the experiment. There were no clinical observations attributable to the treatment with test substance at the middle and lower dose level. There was no difference in body weight increment of all groups in comparison to the vehicle control. The positive control substance DNCB elicited a reaction pattern with statistically significant increase in ear weight and LN hyperplasia, which was in congruence with his expected mode of action as a contact allergen. The test substance showed a tendency to increase of ear weight in the highest dose level but without lymph node hyperplasia. Residues of the test substance on the ears caused this increased weight. Comparison of values between treated groups and control group revealed that the test substance did not cause statistically significant increase in LN cell count or in LN weight. Also index of LN weight and LN cell count was not exceeded in any dose level. In conclusion, at the given experimental conditions the test substance elicited negative result in LLNA test.

Therefore, it is concluded that all 'yellow disazo condensation pigments' are not sensitising to skin and have not to be classified for skin sensitisation.   

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on skin sensitisation, the test item is not classified according to Regulation (EC) No 1272/2008 (CLP), as amended for the tenth time in Regulation (EU) No 2017/776.