A mixture of: tert-alkyl(C12-C14)ammonium bis[1-[(2-hydroxy-5-nitrophenyl)azo]-2-naphthalenolato(2-)]-chromate(1-); tert-alkyl(C12-C14)ammonium bis[1-[(2-hydroxy-4-nitrophenyl)azo]-2-naphthalenolato(2-)]-chromate(1-); tert-alkyl(C12-C14)ammonium bis[1-[[5-(1,1-dimethylpropyl)-2-hydroxy-3-nitrophenyl]azo]-2-naphthalenolato(2-)]-chromate(1-); tert-alkyl(C12-C14)ammonium [[1-[(2-hydroxy-5-nitrophenyl)azo]-2-naphthalenolato(2-)]-[1-[(2-hydroxy-5-nitrophenyl)azo]-2-naphthalenolato(2-)]]-chromate(1-); tert-alkyl(C12-C14)ammonium [[1-[[5-(1,1-dimethylpropyl)-2-hydroxy-3-nitrophenyl]azo]-2-naphthalenolato(2-)]-[1-[(2-hydroxy-5-nitrophenyl)azo]-2-naphthalenolato(2-)]]-chromate(1-); tert-alkyl(C12-C14)ammonium ((1-(4(or 5)-nitro-2-oxidophenylazo)-2-naphtholato)(1-(3-nitro-2-oxido-5-pentylphenylazo)-2-naphtholato))chromate(1-)

Endpoint summary

Description of key information

Based on the blackish discoloration of the whole body, at least the chromophore of the black dye is taken up by in distributed throughout the body. Upon cessation of treatment, the discoloration disappears with time.

Additional information

No experimental toxicokinetic data is available. The product is a mixture of several components with slightly different solubilities and therefore different toxicokinetic profiles. Based on the results of the water solubility determination, non-coloured components with a sum water solubility of 23 mg/L are present. The coloured components are poorly soluble in water at neutral pH (< 5 mg/L) and they are soluble in fat. The stability in the highly acidic environment of the stomach is unkown. It is speculated that paritial disintegration of the coloured complexes occurs.

Repeated oral intake of the test substance at 1000 mg/kg/ bw/day for some animals resulted in reversible purple or blue skin/fur as well as in bluish discolouration of the pancreas and testes. In the screening study for reproductive toxicity, dark discoloration of blood samples was reported indicating transport via the blood. In the absence of any microscopic correlates and given that the test article is a dye stuff, these discolourations were concluded to be due to passive staining and not a toxicological response. The bluish discoloration of the pancreas and testes was observed in three of five males after 28 days. At the end of the recovery period, one male showed bluish discoloration in testes. For females, one of five and none of five animals showed bluish discoloration of the pancreas at the end of the treatment period and after recover, respectively. No discoloration was observed at the doses of 200 and 50 mg/kg bw.

The discoloration pattern indicates uptake after ingestion and elmination via the bile at overload doses. Elimination of the intact dye via the urine is unlikely as this would have resulted in green discoloration, which was not observed.

Apart from the discoloration, signs of systemic toxicity were observed at 200 and 1000 mg/kg bw. These signs do not give a clear picture of target organs and they were reversible within the 14 day recovery period. For details it is referred to the section describing repeated dose toxicity.

Upon cessation of treatment, the discoloration of the animals disappears (BASF 2012).

Overall, it is concluded that the substance is unlikely to have a potential for bioaccumulation.