2-Naphthalenesulfonic acid, 5(or 8)-((4-hydroxy-2-methylphenyl)azo)-8(or 5)-(phenylazo)-, monosodium salt 68039-07-6 EINECS 268-229-0 Sodium (5or8)-((4-hydroxy-2-methylphenyl)azo)-(8or5)-(phenylazo)naphthalene-2-sulphonate