This European Standard specifies a method to assess the resistance to oxidation of a phosphate ester fluid under accelerated oxidizing conditions, together with the corrosive effect on copper and steel during ageing. The means of assessment is the change in acidity of the fluid plus absorbent water and the change in mass of test pieces of copper and steel. The precision of the test method applies to changes in acid number up to 3,0 mg KOH/g and changes in mass of up to 3 mg per test piece.NOTEAccelerated oxidation of fire-resistant fluids based on phosphate esters is characterized by the formation of acid constituents.WARNING - The use of this European Standard may involve hazardous materials, operations and equipment. This European Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this European Standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.