ASTM D3278-21 specifies a standard test method for determining the flash point of liquids using small closed-cup devices. The flash point is the minimum temperature at which liquids can produce flammable vapors during heating and can be ignited. It is an important indicator for evaluating the flammability of liquids. This method is suitable for flash point testing of liquid materials such as Coatings, Solvents, and Miscellaneous Chemicals. The use of small closed-cup devices enables efficient and accurate determination at small sample sizes. Implementation of the standard can help manufacturers and laboratories ensure the safety of chemicals and comply with relevant safety and transportation practices.