Methylethylketoxime (MEKO) is 2-butanone oxime, a clear, colourless liquid with a musty odour. It is used primarily as an anti-skinning agent in alkyd paints, oxidative drying coatings and lacquers to prevent skin formation in the container, as a blocking agent for isocyanate urethane coatings and resins, and as a volatile oxygen scavenger and corrosion inhibitor in boiler water treatment and steam generation.