Acid Red 89 Chemical Name ACID RED 89 C.I. No. 23910 CAS No. 6472-50-0 Synonyms Classic Acid Red 89, Milling Red RA SUB, Orco Milling Red 3BM, Weak Acid Red 3B[U], Xylene Milling Red R Molecular Formula C34H24N4Na2O8S2 Molecular Weight 726.69