Dangers of Liquid Hydrogen

Liquid hydrogen has no color, odor or taste. Although it is non-toxic, liquid hydrogen can cause many safety concerns. These dangers include asphyxiation, fire, explosions and burns from exposure to its extremely cold temperature. Proper safety equipment and protective clothing are important to reduce safety risks when dealing with liquid hydrogen.

Asphyxiation

• Asphyxiation is defined as loss of consciousness or death due to normal breathing being impaired. Liquid hydrogen can cause asphyxiation from vapors escaping into the air. These vapors, or fumes, cause an oxygen-deprived environment if not properly ventilated. Asphyxiation can be prevented if proper ventilation is created in areas where liquid hydrogen will be kept or moved through. While liquid hydrogen may be in closed containers or systems to prevent fumes, spills and leaks can happen. It is especially important to have ventilation systems in place for accidental exposure to liquid hydrogen because in these instances you are less likely to have safety equipment on.

Fire

• Liquid hydrogen is highly flammable when exposed to air. It takes only four percent of the air being made up of hydrogen fumes to be flammable. Even a slight leak in a liquid hydrogen container can mean extreme fire danger. Hydrogen is easily ignited. Sources of ignition, such as open flame, electrical equipment, static electricity and hot objects should be eliminated from areas that have liquid hydrogen in them. Burns can result from fires that are almost invisible. These invisible fires exist because hydrogen burns with a light blue flame that is harder to see than yellow or orange flames.

Explosion

• Liquid hydrogen can become combustible if mixed with other gasses or liquids. This mixing usually occurs when a liquid hydrogen leak occurs and mixes with other gasses in the air. When the mixture becomes combustible, it can explode without notice, especially since hydrogen is easily ignited. Merely walking into a room with a combustible mixture can cause it to ignite due to static electricity. Burns, fires and property destruction can result from explosions. Combustible mixtures can be prevented with proper ventilation and safety precautions taken.

Cold Burns

• Hydrogen is fully liquid at negative 423 degrees Fahrenheit. Because of its extremely cold temperature, cold burns can occur when handling liquid hydrogen. The most common places where exposure to the cold temperatures occurs is contact with frosted lines used to move the hydrogen through a closed system, vapor leaks or liquid (condensed) air dripping from ventilation stacks or cold lines. It only takes a couple seconds of exposure to such an extreme low temperature to cause a burn. You should wear protective clothing to prevent exposure to the cold and avoid cold burns.