It is difficult with our human senses to have ready awareness of small quantities of released hydrogen gas or a hydrogen fire. Hydrogen is colorless, odorless, burns with a nearly invisible flame (especially during daylight hours), and gives off relatively little radiant heat. Even though substantial thought may have gone into a system design to benefit safety, personnel approaching laboratories or equipment containing hydrogen should confirm that a flammable mixture or hydrogen fire is not present.

  • Before entering the proximity of hydrogen-containing laboratories or equipment, consult the status of fixed gas sensors and flame detectors.
  • Always use PPE before attempting to operate hydrogen-containing equipment.
  • Without fixed sensors, thermal imaging cameras can verify that a hydrogen flame is present. If a flame is not present, confirm with a personal gas detector that flammable mixtures are not present.
  • If these tools are not available, personnel should assume a leak. Watch for thermal waves that signal the presence of a flame. Use combustible objects (e.g., a broom can be convenient) or toss dust particles into the flame, which will emit in the visible spectrum. Certain environments such as salt air found near the ocean, will produce a blue-tinted flame due to the presence of sodium.

Although hydrogen fires do not produce smoke themselves, burning of nearby combustible materials can result in smoke. Thus, personnel should be aware that smoke inhalation can be a danger in a hydrogen fire.