Synonyms: 2,7-Naphthalenedisulfonicacid, 3-amino-4-[[4'-[(2,4-diamino-5-nitrophenyl)azo]-4-biphenylyl]azo]-,disodium salt (8CI); 2,7-Naphthalenedisulfonic acid,3-amino-4-[[4'-[(2,4-diamino-5-nitrophenyl)azo][1,1'-biphenyl]-4-yl]azo]-,disodium salt (9CI); C.I. 22070; Pyramine Orange RR