GB/T 9343 - 2008 is used to determine the flash and spontaneous combustion temperature of plastics. This standard describes the test principle, puts forward technical requirements for test devices such as heating furnaces and temperature measurement meters, specifies the preparation method of plastic samples, and standardizes the heating rate, observation interval and other test procedures. Through this standard, the flash and spontaneous combustion temperature data of plastics can be accurately obtained, which provides a basis for plastic manufacturers to evaluate the fire risk of products and develop flame retardant formulas. It also provides a reference for the rational selection of materials in the plastic application industry, and helps to improve the fire safety performance of plastic products in use.