Metal powder can't be put out with water when it is on fire. Adding water may produce a chemical reaction, and the combustion will be more intense. Dry sand, lime, etc. can be used. (no impact); The accumulated dust, such as flour, cotton and linen powder, may still smolder inside after the open flame is extinguished, and it should also be paid enough attention; For large-area and long-distance workshop dust fires, effective segmentation measures should be taken to prevent the fire from spreading along the deposited dust or causing chain explosions.