1-Hydroxy-3-naphthalenesulfonic acid 1-Naphthol, 3-sulfo- 1-Naphthol-3-sulfonic acid 2-Naphthalenesulfonic acid, 4-hydroxy- 3771-14-0 4-Hydroxy-2-naphthalenesulfonic acid 4-Hydroxynaphthalene-2-sulphonic acid EINECS 223-212-7 NSC 37039