A lubricant composition for use in a sliding-vane rotary vane compressor has a polyalkyleneglycol base oil component and includes antiwear additives, antioxidants and metal passivators and, optionally, anticorrosion agents and vapour phase anticorrosion agents. The polyalkyleneglycol base oil component is a random copolymer of ethylene oxide (EO) and propylene oxide (PO) having an EO:PO ratio between 3:1 and 1:3, preferably between 1.5:1 and 1:1.5, and having been initiated with a compound having five carbon atoms or less.