1-Naphthalenesulfonic acid, 3-hydroxy-4-((1-hydroxy-2-naphthalenyl)azo)-7-nitro- 25747-08-4 3-Hydroxy-4-((1-hydroxy-2-naphthalenyl)azo)-7-nitro-1-naphthalenesulfonic acid 3-Hydroxy-4-((1-hydroxy-2-naphthyl)azo)-7-nitronaphthalene-1-sulphonic acid EINECS 247-237-8