Lab Safety

Water-reactive Materials

What are water reactive materials?

Water reactive substances are dangerous when wet because they undergo a chemical reaction with water. This reaction may release a gas that is either flammable or presents a toxic health hazard. In addition, the heat generated when water contacts such materials is often enough for the item to spontaneously combustor explode.

 How should I handle water reactive materials?

  • Always wear safety goggles, gloves, lab coat and closed toe shoes
  • Use a fume hood if there is a possibility of gases forming in the reaction
  • Store in a cool dry area away from other chemicals
  • Wash hands and work station after use

Here are some examples of water-reactive materials:


Name/Description CAS Number
Aluminum alkyl halides  
Aluminum alkyl hydrides  
Aluminum alkyls  
Aluminum borohydride or Aluminum borohydride in devices 16962-07-5
Aluminum Carbide 1299-86-1
Aluminum ferrosilicon powder  
Aluminum hydride 7784-21-6
Aluminum phosphide 20859-73-8
Aluminum powder, uncoated 7429-90-5
Aluminum silicon powder, uncoated  
Barium 7440-39-3
Boron trifluoride dimethyl etherate 353-42-4
Calcium 7440-70-2
Calcium carbide 75-20-7
Calcium cyanamide with more than 0.1 percent of calcium carbide 156-62-7
Calcium hydride 7789-78-8
Calcium manganese silicon  
Calcium phosphide 1305-99-3
Calcium silicide 12737-18-7
Cells, containing sodium  
Cerium, turnings or gritty powder 7440-45-1
Cesium or Caesium 7440-46-2
Dimethylzinc 544-97-8
Ethyldichlorosilane 1789-58-8
Ferrosilicon, with 30 percent or more but less than 90 percent silicon 8049-17-0
Lithium 7439-93-2
Lithium alkyls  
Lithium aluminum hydride 16853-85-3
Lithium aluminum hydride, ethereal 16853-85-3
Lithium borohydride 16949-15-8
Lithium ferrosilicon 70399-13-2
Lithium hydride 7580-67-8
Lithium hydride, fused solid 7580-67-8
Lithium nitride 26134-62-3
Lithium silicon 68848-64-6
Magnesium alkyls  
Magnesium aluminum phosphide  
Magnesium granules, coated, particle size not less than 149 microns 7439-95-4
Magnesium hydride 7693-27-8
Magnesium phosphide 12057-74-8
Magnesium silicide 22831-39-6
Magnesium, powder or Magnesium alloys, powder 7439-95-4
Maneb or Maneb preparations with not less than 60 percent maneb 12427-38-2
Methyl magnesium bromide, in ethyl ether  
Methyldichlorosilane 75-54-7
Phosphorus pentasulfide, free from yellow or white phosphorus 7723-14-0
Potassium 7440097
Potassium borohydride 13762-51-1
Potassium phosphide 20770-41-6
Potassium sodium alloys 1113581-2
Potassium, metal alloys 7440097
Rubidium 7440-17-7
Sodium 7440-23-5
Sodium aluminum hydride 13770-96-2
Sodium borohydride 16940-66-2
Sodium hydride 7646-69-7
Sodium phosphide 24167-76-8
Stannic phosphide 25324-56-5
Strontium phosphide 12504-13-1
Trichlorosilane 10025-78-2
Zinc ashes  
Zinc phosphide 1314-84-7
Zinc powder or Zinc dust


Page last modified March 13, 2014