PEL-LUBE 591 metalworking lubricant is a polyalkylene glycol formulated with an EP phosphate ester. It provides both hydrodynamic and extreme pressure lubrication. PEL-LUBE 591 is completely water soluble at ambient temperatures. At elevated temperatures it exhibits inverse solubility and is thus able to provide excellent lubricity at low aqueous concentrations. When PEL-LUBE 591 is compounded with alkanolamines, corrosion inhibitors, and biocides, synthetic coolants of exceptional performance and versatility can be produced. It is hydrolytically stable and resists microbial attack.