| Description | Solvent Red 23 is an oil-soluble red azo dye used in cosmetic products in Japan. Cases were reported in hairdressers, who also reacted to PPD and to paminoazobenzene. One case of contact dermatitis was reported in the metal industry. |
| Chemical Properties | reddish brown powder |
| Uses | Dye. Biological stain. |
| Uses | Weakly acidic azo dye. Biological stain. Dyes and metabolites, Environmental Testing. |
| Uses | Weakly acidic azo dye. Biological stain. |
| Definition | ChEBI: A bis(azo) compound that is 2-naphthol substituted at position 1 by a 4-{[(2-methylphenyl)diazenyl]phenyl}diazenyl group. A fat-soluble dye predominantly used for demonstrating triglycerides in frozen sections, but which may also stain some protein bound l pids in paraffin sections. |
| Preparation | 4-(Phenyldiazenyl)benzenamine diazotization, and Naphthalen-2-ol coupling. Note: some goods by 4-(Phenyldiazenyl)benzenamine and 2-Methyl-4-(o-tolyldiazenyl)benzenamine mixture as diazo components and have to. |
| Contact allergens | Solvent Red 23 is an oil-soluble red azo-dye used in cosmetic products in Japan. Cases were reported in hairdressers, who also reacted to PPD (the molecule is likely to be hydrolyzed into PPD) and to p-aminoazobenzene. One case of contact dermatitis was reported in the metal industry. |
| Safety Profile | Poison by intraperitoneal route. Moderately toxic by subcutaneous and intrapleural routes. Questionable carcinogen. Mutation data reported. When heated to decomposition it emits toxic fumes of NOx. |
| Purification Methods | Crystallise the dye from EtOH, EtOH/water or *benzene/absolute EtOH (1:1). [Beilstein 16 II 75, 16 III 148, 16 IV 248.] |
| Properties and Applications | yellow red to red. Soluble in ethanol and acetone, soluble in benzene. In concentrated sulfuric acid to blue light green, dilution for blue solution, and a red precipitation.
StandardLight FastnessHeat-resistant(℃)waterSodium Carbonate(5%)Hydrochloric acid(5%)Melting pointStableISOGood19570≥ 120SublimationInsolubleNo changeNo change |
