C.I. Reactive Red 1; C.I. Reactive Red 1, trisodium salt; C.I. Reactive Red 1, trisodium salt (8CI); Procion Brilliant Red M-2BS; (3E)-5-[(4,6-dichloro-1,3,5-triazin-2-yl)amino]-4-oxo-3-[2-(2-sulfophenyl)hydrazinylidene]-3,4-dihydronaphthalene-2,7-disulfonic acid; trisodium (3E)-5-[(4,6-dichloro-1,3,5-triazin-2-yl)amino]-4-oxo-3-[2-(2-sulfonatophenyl)hydrazinylidene]-3,4-dihydronaphthalene-2,7-disulfonate