The standard EN ISO 3679-2015 flash point, no flash point determination, closed-cup fast equilibrate method specifies a method for determining the flash point of liquids using the closed-cup fast equilibrate method. This method determines the flash point by heating the sample in a closed container to a gradually increasing temperature, when the vapor of the liquid is mixed with air and can be ignited. Compared with traditional methods, the closed-cup fast equilibrate method improves the efficiency and accuracy of measurement through the fast equilibrate technology. This method is suitable for various petroleum products and chemical liquids, especially in the application of safety assessment and hazard classification. The standard provides detailed operating procedures and instrumentation requirements to ensure conformity and repeatability of test results.