Lithium Aluminum Hydride Fire

Key Instruction Points

  • Know the hazards of the materials, including appropriate extinguishing agents, before using chemicals. 

  • Carbon dioxide reacts with LAH explosively; thus, a carbon dioxide extinguisher could have made the situation worse. A Met-L-X fire extinguisher (for flammable solids) or dry sand should have been immediately available.

  • Do not pour solids such as LAH directly from the container into another chemical or reaction vessel. Measure out what is needed, then pour it.

A laboratory worker was attempting to distill tetrahydrofuran (THF) using lithium aluminum hydride (LAH). THF is a highly flammable liquid that can cause severe eye irritation and central nervous system depression. LAH is a water-reactive, flammable solid.  

The laboratory worker was slowly pouring approximately 1 gram of LAH from a plastic bag into a flask containing 500 ml of THF inside a fume hood. A small amount of LAH leaked from a small hole in the bag, onto the surface of the hood and burst into flames, startling the worker and causing him to drop the remainder of the bag (8-10 grams of LAH) onto the fire. Concerned about the flask and bottle of THF inside the hood, the worker immediately removed his lab coat and placed it onto the fire in an attempt to smother it.  

Since the appropriate extinguishing agent was not available, .the worker pulled the flaming lab coat and LAH out of the hood onto the floor. Once the LAH fire had burned itself out, the worker used a dry chemical extinguisher to put out the coat fire.