3,3'-[(2-chloro-5-methyl-p-phenylene)bis[imino(1-acetyl-2-oxoethylene)azo]]bis[4-chloro-N-[2-(4-chlorophenoxy)-5-(trifluoromethyl)phenyl]benzamide]

Endpoint summary

Description of key information

Not irritating on rabbit skin (OECD 404)

Not irritating in rabbit eyes (OECD 405)

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There are reliable studies available to assess the skin and eye irritation potential of the Pigment Yellow 128 and related substances. The studies were performed in 1973 and 2011when characterization of powders in regard to particles with a size of < 100 nm was not routinely performed. Retrospective analysis of the products indicates that one test material used for eye irritation testing was a nanomaterial wheras for the other materials, no conclusions could be drawn. Therefore, information on the whole range of organic pigments is taken into account.  

 

 Organic pigments, which are powders that often have a nanosize fraction, consistently show absence of a hazard for skin and eye irritation (Stratmann, et al. Indicators for lack of systemic availability of organic pigments, https://doi.org/10.1016/j.yrtph.2020.104719, Regulatory Toxicology and Pharmacology Volume 115, August 2020, 104719). The publication lists 106 and 107 pigments tested for skin ande eye irritation, respectively and for of them, the classification critieria as an irritant were not met.  

  

 The question on the impact of the particle size on the suitability of the in-vitro studies for eye irritation was adressed in the publication by Kolle et al in 20016 (Eye irritation testing of nanomaterials using the EpiOcular™ eye irritation test and the bovine corneal opacity and permeability assay, DOI 10.1186/s12989-016-0128-6, Particle and Fibre Toxicology (2016) 13:18). None of the dry-powder nanomaterials elicited eye irritation in either the EpiOcular™-EIT or the BCOP assay which was consistent with available in vivo data for the same test materials or for nanosized or bulk materials of the same composition.

Therefore, the available experimental data is considered adequate to assess the hazard of the pigment both in the bulk and in the nano form. 

   

The following gives a short summary on the irritation data on Pigment Yellow 128 itself and on related pigments.

Skin:

Reliable data from several studies on skin irritation are available for four members of the 'yellow disazo condensation pigments' (CAS 5580-57-4, 5280-80-8, 68516-73-4, 79953-85-8). These data reveal a very low skin irritation potential for the 'yellow disazo condensation pigments'. In a primary dermal OECD guideline irritation study (OECD 404, Ciba-Geigy Ltd., 1983), 3 female New Zealand White rabbits were dermally exposed to 0.5 g of the test substance (CAS 5280-80-8) for 4 hours under semiocclusive conditions. Animals then were observed for 7 days. Irritation was scored by the method of Draize as described in the OECD guideline 404. The mean score for the 24, 48 and 72 h reading for erythema was 0.44 and for edema was 0. The skin reactions observed were fully reversible within 48 hours. Under the conditions of the present experiment the test substance (CAS 5280-80-8) was found to be non-irritant and not corrosive when applied to the rabbit skin. For three further test substances of the 'yellow diazo condensation pigments' (CAS 5580-57-4, 68516-73-4, 79953-85-8) similar results were found although the treatment was under more severe conditions: On the intact skin (flanks) of three rabbits 0.5 g of the substance, moistened with tap water or polyethylene glycol, was applied onto skin for 24h under occlusive conditions.Observations 24h, 48h, 72h, after treatment did not reveal formation of erythema or edema or only light erythema.

No reliable study on skin irritation of one 'yellow diazo condensation pigment' (CAS 5580-58-5) is available. But due to the consistent observation that the other disazocondensation yellow pigments do not induce skin irritation it is concluded that this member is also not irritating to skin. In summary, it is concluded that 'yellow disazo condensation pigments' are not irritating to skin and have not to be classified as skin irritants.

 

Eye:

Reliable data from studies on eye irritation with the target substance and three source substances are available for the 'yellow disazo condensation pigments' (CAS 5580-57-4, 5280-80-8, 68516-73-4). These data reveal a low eye irritation potential for the 'yellow disazo condensation pigments'. Eye irritation tests according to OECD guideline 405 were done with two 'yellow diszo condensation pigments' (CAS 5280-80-8 (Ciba-Geigy Ltd., 1983) and CAS 68516-73-4 (Dominion, 2011)). The tests were performed with three New Zealand White rabbits. Eyes were left unwashed after application of 0.1 g or 0.1 mL (0.03 g) of test substance, respectively and the animals were observed 7 days or 72 hours, respectively. For test substance with CAS 5280-80-8 the mean scores for the 24, 48 and 72 h reading for conjunctivae redness, corneal opacity, iritis, and conjunctivae chemosis were 0.1, 0.1, 0, and 0.3, respectively. After 72 hours all reactions were fully reversed. Under the conditions of the present experiment the test substance was found to be slightly irritant and not corrosive when applied to the rabbit eye mucosa. There was a clear tendency of recovery towards the end of the observation period and no classification according to EU- or EU-GHS-requirements is necessary. The scores for the test substance with CAS 68516-73-4 were all 0 for conjunctivae redness, corneal opacity, iritis, and conjunctivae chemosis. For two further test substances of this 'yellow diazo condensation pigments' (CAS 5580-57-4 (BASF, 379/45, 1975), 79953-85-8 (BASF, 79953-85-8, 1973)) reliable studies were done which were similar to OECD guideline 405. They also showed only slight or no irritation to the pigments.

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 irritation/corrosion and eye irritation, 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.