Specifies the characteristics of unused triaryl phosphate ester fluids for turbine governor controls and other hydraulic systems in electrical power stations. Fluids used in this application are classified under category TCD of ISO 6743-5. The major changes with regard to the first edition concern the need to upgrade the report to an International Standard, taking account of changes to the specification. The changes made include: a) introduction of new tests to define fire resistance, namely the Manifold Ignition and Wick flame persistence tests; b) flame persistence tests; c) introduction of a pour point requirement; d) a change to the Sequence II foaming requirement; e) introduction of a cleanliness requirement; f) introduction of an elastomer compatibility requirement; g) use of ISO test methods equivalent ot the original DIN tests.