Is aluminum powder flammable

Aluminum powder is flammable and can form explosive mixtures in air. If moisture is present the hazard is greater. Poisonous gases are produced in fire, including aluminum oxide fumes. Fire may restart after it has been extinguished.

Aluminum powder, pyrophoric is a reducing agent. 

Reacts very exothermically when mixed with metal oxides and ignited or heated (thermite process). Reacts explosively when mixed with copper oxides and heated. Reacts with metal salts, mercury and mercury compounds, nitrates, sulfates, halogens, and halogenated hydrocarbons to form compounds that are sensitive to mechanical shock. 

Mixtures with ammonium nitrate are used as an explosive. 

A mixture with powdered ammonium persulfate and water may explode. Heating with bismuth trioxide leads to an explosively violent reaction. Mixtures with finely divided bromates (also chlorates and iodates) of barium, calcium, magnesium, potassium, sodium or zinc can explode by heat, percussion, and friction. Burns in the vapor of carbon disulfide, in sulfur dioxide, sulfur dichloride, nitrous oxide, nitric oxide, or nitrogen peroxide. A mixture with carbon tetrachloride exploded when heated to 153°C and also by impact. Mixing with chlorine trifluoride in the presence of carbon results in a violent reaction. Ignites in close contact with iodine. Three industrial explosions involving a photoflash composition containing potassium perchlorate with aluminum and magnesium powder have occurred . React with methyl chloride in the presence of small amounts of aluminum chloride to give flammable trimethylaluminum. 

Gives a detonable mixture with liquid oxygen. 

The reaction with silver chloride, once started, proceeds with explosive violence. In an industrial accident, the accidental addition of water to a solid mixture of sodium hydrosulfite and powdered aluminum caused the generation of SO2, heat and more water. The aluminum powder reacted with the water and other reactants leading to an explosion that killed five workers. Particles can become electrostatically charged if swirled, transported by pneumatic means or poured.