flash point

Definition

Temperature at and above which a liquid gives off enough flammable vapor to form a mixture with air that can be ignited by contact with a hot surface, spark, or flame. Lower the flash point, greater the fire hazard. Common test methods of determining flash point include Pensky-Marten Closed Tester (ASTM D93-79), Setaflash Closed Tester (ASTM D3278-78), and Tag Closed Tester (ASTM D56-79). Since each test method may yield a different reading, the test method employed is usually indicated when a liquid's flash point is given in a material safety data sheet (MSDS) or in technical documents. Flash point should not be confused with auto-ignition point temperature at which combustion occurs spontaneously, without an external source of ignition.