Sodium Hydride

Key Instruction Points

  • Fires involving reactive chemicals may not be extinguishable by the carbon dioxide (BC) or dry chemical (ABC) extinguishers typically provided to laboratories. If water reactive chemicals are used or stored in the laboratory, consider keeping a small amount of sand or limestone on hand.   

  • Consult the manufacturer’s safety data sheets for the recommended type of extinguisher for these materials. 
  • Fume hoods in many newer laboratory buildings are sprinklered. Sprinkler activation during a fire will exacerbate the situation when a water-reactive chemical is involved. It is best to let this type of fire burn itself out rather than attempting to fight it yourself. Lower the sash if possible, leave the area, and activate the building fire alarm. Call your institution’s emergency phone number from a safe location and provide details about the fire. 

Sodium hydride (NaH) can react with water or spontaneously with moist air to generate highly flammable hydrogen gas and corrosive sodium hydroxide. A few months ago, a graduate student was attempting to convert some unneeded NaH into a less reactive compound, a process known as quenching, prior to disposing it. The reaction was conducted in an ice bath and when the extreme heat liberated by the process ruptured the reaction beaker, a brief, though very intense fire occurred. Fortunately, no one was injured.  

This accident provides a backdrop for considering the following points about procedures for hazardous waste disposal, fire safety, and working with chemicals posing particular hazards. 

Many chemicals used in the laboratory, including NaH, are legally considered regulated hazardous waste once they are designated for disposal. Many Research Institutions are not licensed to treat (e.g., quench) such waste on site. Contact your safety office to arrange for the safe and legal disposal of hazardous chemicals through your institution’s hazardous waste vendor.