Beo (butynediol ethoxylate) Beo (butynediol ethoxylate) Beo, butynediol ethoxylate, cas no.1606-85-5, c8h14o4 Appearance: clear yellowish to red brown liquid Assay:98% Density g/cm3 (20): 1.11~1.16 Ph: 4.0~7.0 Refractive index(20): 1.4740~1.4840 Application: lasting brightener, weak leveling agent for nickel plating