What is the flash point below which is flammable?

The flash point of a flammable gas is less than or equal to 28 degrees, and the flash point represents one of the properties of flammable liquids. If it is lower than 28.1°C, it is a first-class flammable liquid, which is extremely flammable and volatile, such as gasoline, etc.; the flash point is 28.1-45 °C is a secondary flammable liquid, easy to burn and volatilize, such as kerosene, turpentine, etc. Compared with flammable liquids and solids, flammable gases are easier to burn, and the burning speed is fast. The gas composed of simple components is more flammable, burns faster, has higher flame temperature, and is more dangerous to fire and explode than the gas composed of complex components.