SUMMARY Butyl Cellosolve * (C4H9OCH2CH2OH-2-butoxyethanol) is a glycol ether with excellent solvent power for many of the resins used in surface coatings. It is a useful coupling agent, because it is miscible with water and with most solvents and many oils. In surface- coatings it imparts blush resistance, gloss, and good flow-out. It is also employed in metal cleaners, dry-cleaning soaps, and hydraulic fluids. Butyl Cellosolve has a specific gravity of 0.9019 at 20/20 C, a boiling point of 171.2 C, and a vapor pressure of 0.76 mm. Hg at 20 C. Vapor-saturated air at room temperature has a concentration of the order of 1000 ppm butyl Cellosolve. Its relative evaporation rate is 1, in a scale in which that of Cellosolve is 5, butyl alcohol, 7, methyl Cellosolve, 8, xylene, 10, toluene, 40, and acetone, 200.