This International Standard specifies the minimum requirements for turbine lubricants, as delivered. It specifies the requirements for a wide variety of turbines for power generation, including steam turbines, gas turbines, combined-cycle turbines with a common lubrication system and hydraulic (water driven) turbines. This International Standard does not specify the requirements for wind turbines, which are dealt with in ISO 12925-1W. Whilst power generation is the primary application for turbines, steam and gas turbines can also be used to drive rotating equipment, such as pumps and compressors. The lubrication systems of these driven loads can be common to that of the turbine. Turbine installations incorporate complex auxiliary systems requiring lubrication, including hydraulic systems, gearboxes and couplings. Depending upon the design and configuration of the turbine and driven equipment, turbine lubricants can also be used in these auxiliary systems. This International Standard should be read in conjunction with ISO 6743-5I2!, the classification of different turbine lubricant types. The following lubricants are considered in this International Standard: — mineral oils; — synthetic lubricants, ester and polyalphaolefin types intended for high-temperature gas turbines; — synthetic lubricants, ester and polyalphaolefin types, environmentally acceptable for use in hydraulic turbines; — fire-resistant phosphate-ester type lubricants. NOTE For the purposes of this International Standard, the term "% (m/m)" is used to represent the mass fraction.