Causes of burning: The heat generated by the water cannot be dissipated in time to reach the ignition point of the insurance powder.
Sodium dithionite (commonly known as insurance powder) can spontaneously ignite at 250 degrees. It can be burnt when exposed to open flames. It can release a lot of heat and burn when it meets water and acid, and emits sulfur dioxide odor.
The powder is not insured, in fact it is a highly reactive substance. If the powder is exposed to a small amount of water or exposed to humid air, it will decompose and heat. If the heat generated by the decomposition cannot be dissipated in time to form heat accumulation, it will cause a fire or explosion accident and release toxic sulfur dioxide. When the temperature reaches 250 degrees Celsius, it can spontaneously ignite. Contact with oxidizing agents can react violently, causing a burning explosion.