Policy or Procedure for Storing Helium

Helium is the second lightest element and is used for a variety of commercial and industrial purposes including welding, airships and cooling superconducting magnets such as those used in Magnetic Resonance Imaging scanners. Helium is nontoxic, but compressed and liquid helium must be stored properly to avoid human injury.

Compressed Helium

• Helium is an inert gas, meaning it does not combine or react with other elements under normal circumstances. While no special precautions need be taken when storing helium in the gaseous state because of its nonreactivity, any compressed gas needs to be stored and handled with care. Keep compressed helium cylinders in an upright position in a well-ventilated area. Store helium away from high pedestrian and vehicular traffic areas and protect the steel cylinders from corrosion by salt or weather. Keep compressed helium below 125 degrees F to prevent expansion of the gas. Protect the canisters’ valves with the appropriate metal covers. Proper helium storage procedures ensure that the oldest cylinders are used first and that stored canisters are inspected regularly for signs of damage. Label stored helium with its Chemical Abstracts Service (CAS) number of 7440-59-7 and its UN ID code of UN1046. Clearly label full and empty containers. Use a hand cart to transport compressed helium cylinders and never roll or drag compressed gas containers.

Liquid Helium

• Large quantities of helium are stored and transported in liquefied form, since liquid helium is five times denser than the compressed gaseous form. Liquefied helium is stored at low temperatures at high pressures. Store liquid helium in a container designed to meet or exceed American Society of Mechanical Engineers or U.S. Department of Transportation standards. Observe similar procedures as compressed gaseous helium, including storing in a ventilated area and keeping containers upright. However, the cold temperatures at which liquid helium is stored mandate additional safety procedures. Require training for any staff who must use, transfer or move liquid helium, including the use of protective equipment such as a facial shield and safety goggles, insulated gloves and safety boots or shoes. Inspect tanks and valves at least once a month for frost buildup or signs of corrosion or other damage.

Asphyxiation Hazard

• Helium is lighter than air, but high concentrations of the gas can displace oxygen and cause unconsciousness and death without warning. Good storage procedures will minimize the risk of asphyxiation, but provide emergency gear such as self contained breathing apparatus if helium is stored or used in a poorly ventilated area.