Abstract: A solvent blend cleaner useful for reflux cleaning of chemical manufacturing equipment, including that used in manufacturing pharmaceuticals, comprises a blend of environmentally friendly and safe solvents selected on the basis of specific criteria, such as vapor pressure, vapor density, boiling point, specific heat, and heat of vaporization, among other things; achieves excellent cleaning even upon further dilution with water; and avoids the disadvantages associated with the use of conventional commodity solvents in reflux cleaning methods. Desired solvency, cleaning and wetting properties of the inventive formulations in use can be achieved through blending of solvents having the selected criteria. Additives, such as surfactants, can be added to enhance cleaning and lower solvent requirements.