An aromatic hydrocarbon molecule containing a benzene ring with two methyl side chains, formula C6H4(CH3)2. Xylene is an excellent solvent, especially for aromatic solids such as asphaltic materials. It is used as a solvent and emulsion breaker in workover operations to clean up reservoirs. In drilling mud testing, a 50/50 xylene/isopropanol (IPA) mixture had been used to break oil-mud emulsions prior to titrations to measure alkalinity, chloride and calcium. However, the xylene mixture has been replaced by a single material, propylene glycol normal propyl ether (PNP), to break oil mud emulsions.