Synonyms: 2,7-Naphthalenedisulfonicacid, 4,5-dihydroxy-3,6-bis[(2-hydroxy-5-nitro-3-sulfophenyl)azo]- (8CI,9CI);4,5-Dihydroxy-3,6-bis(2-hydroxy-3-sulfo-5-nitrophenylazo)-2,7-naphthalenedisulfonicacid; Nitrosulfophenol C; Nitrosulfophenol S; 2,7-Naphthalenedisulfonicacid, 4,5-dihydroxy-3,6-bis[2-(2-hydroxy-5-nitro-3-sulfophenyl)diazenyl]-