Synonyms: 2-Naphthalenesulfonicacid, 5-[(2,4-dimethylphenyl)azo]-6-hydroxy-, monosodium salt (9CI);2-Naphthalenesulfonic acid, 6-hydroxy-5-(2,4-xylylazo)-, monosodium salt (8CI);2-Naphthalenesulfonic acid, 6-hydroxy-5-(2,4-xylylazo)-, sodium salt (7CI)