2-Naphthalenesulfonicacid,4,7-dihydroxy, 4,7-dihydroxy-naphthalene-2-sulfonic acid, EINECS 228-759-5, 4,7-Dihydroxy-naphthalin-2-sulfonsaeure, Dioxy-J acid, 3,8-Dihydroxy-6-naphthalenesulfonic acid, 2,5-Dihydroxy-naphthalin-7-sulfonsaeure, 1,6-Dihydroxynaphthalene-3-sulfonicacid, 4,7-Dihydroxynaphthalene-2-sulphonic acid