Butynediol ethoxylate CAS:1606-85-5 BEO (Butynediol ethoxylate) (C8H14O4) CAS No.1606-85-5 Appearance: Clear yellowish to red brown liquid Assay:â?¥98% Application: Lasting brightener, weak leveling agent for nickel plating Density g/cm3 (20): 1.11~1.16 PH: 4.0~7.0 Refractive Index(20): 1.4740~1.4840