2918-80-1 3-(2,4-Dihydroxyphenylazo)-4-hydroxybenzenesulfonic acid 3-(2,4-Dihydroxyphenylazo)-4-hydroxybenzenesulphonic acid Benzenesulfonic acid, 3-((2,4-dihydroxyphenyl)azo)-4-hydroxy- C.I. Mordant Red 5 EINECS 220-855-5 Mordant Red 5 NSC 97024