Synonyms: 2,7-Naphthalenedisulfonicacid, 4,5-dihydroxy-3-[(4-sulfophenyl)azo]-, trisodium salt (9CI);2,7-Naphthalenedisulfonic acid, 4,5-dihydroxy-3-[(p-sulfophenyl)azo]-,trisodium salt (8CI);1,8-Dihydroxy-2-[4-sulfophenylazo]-naphthalene-3,6-disulfonic acid;3-(4-Sulfophenylazo)-4,5-dihydroxynaphthalene-2,7-disulfonic acid trisodiumsalt;Trisodium2-(p-sulfophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonate;