Facts:

  • Hydrogen has a high lower flammability limit and a high flammability temperature (4% and 580 °C, respectively), but is flammable over a wide range. It is easily ignited on ignition.
  • There is little chance of ignition in an open space due to the rapid dissipation of hydrogen due to its low density.
  • Does not form fuel "puddles".
  • Does not float on the surface of the extinguishing agent.
  • Hydrogen burns at high temperatures but very quickly. If there is no combustible material nearby, the fire will quickly go out.
  • Hydrogen flames are difficult to extinguish and can spread quickly.
  • Hydrogen flame emits little heat and is less likely to cause burns.