text: Despite its widespread use as a metal degreaser, trichloroethylene itself is unstable in the presence of metal over prolonged exposure. As early as 1961 this phenomenon was recognized by the manufacturing industry when stabilizing additives were added to the commercial formulation. Since the reactive instability is accentuated by higher temperatures, the search for stabilizing additives was conducted by heating trichloroethylene to its boiling point under a reflux condenser and observing decomposition. Definitive documentation of 1,4-dioxane as a stabilizing agent for TCE is scant due to the lack of specificity in early patent literature describing TCE formulations. Epichlorohydrin, butylene oxide, N-methylpyrrole and ethyl acetate are common stabilisers for TCE, with epichlorohydrin being the most persistent and effective. Other chemical stabilizers include ketones such as methyl ethyl ketone.