Synonyms: Pyridinium,1,1'-[(6,13-dichloro-4,11-disulfo-3,10-triphenodioxazinediyl)bis[imino-2,1-ethanediylimino[6-[(2,5-disulfophenyl)amino]-1,3,5-triazine-4,2-diyl]]]bis[3-carboxy-,bis(inner salt), hexasodium salt (9CI); Pyridinium,1,1'-[(6,13-dichloro-4,11-disulfo-3,10-triphenodioxazinediyl)bis[imino-2,1-ethanediylimino[6-[(2,5-disulfophenyl)amino]-1,3,5-triazine-4,2-diyl]]]bis[3-carboxy-,dihydroxide, bis(inner salt), hexasodium salt; Triphenodioxazine, pyridiniumderiv.; C.I. 51307; C.I. Reactive Blue 187; Procion Blue HE-G; Reactive Blue187