Compressed Gases

Dangers from Compressed Gases

Compressed gas cylinders are common in the laboratory environment. Here are some hazards associated with gas cylinders. For more information, the University Office of Environmental Health and Safety has a video on handling gas cylinders.



Compressed gases can displace oxygen causing injury or death. Oxygen deficiency cannot be sensed by your nose so it is recommended that oxygen level sensors be used in enclosed areas where gas build-up may occur.


Fire and Explosion

Compressed gases may be flammable or accelerate fires or explosions. Oxygen may turn a small fire into an explosion.


Chemical Reaction

Some gases may be very corrosive. Others may be very reactive. Use the correct regulator for gases; never mix regulators. The CGA fitting is specific for each type of regulator. Never mix oxygen regulators and tubing with other regulators and tubing. Acetylene forms explosive compounds with copper.



Many gases are toxic. They are often odourless and colourless such as carbon monoxide. A leak could be deadly. Review the MSDS that came with the gas.


High Pressure

Tubing and containers may explode if put under high pressure. High pressure tubing and manifolds must be inspected by the TSSA under the Ontario Technical Standards & Safety Act. Always pressurize systems slowly. Wear safety goggles.


Improper Handling

Compressed gas cylinders are heavy and awkward to handle. A falling cylinder can cause serious injury and if the valve is knocked off, the cylinder can become a rocket.


Penetrating Skin

Compressed gases can penetrate the skin. Do not use compressed air to blow objects clean; the flying debris can go into eyes.



  • Do read the MSDS that came with the gas.
  • Do use a cart or trolley to transport the cylinder. The cylinder should be strapped securely.
  • Do remove gauges and cap the cylinder before transport. 
  • Do wear proper shoes when moving cylinders, not sandles or open toe.
  • Do keep cylinders strapped securely or chained so they will not fall over. 
  • Do use safety goggles when opening the regulator the first time. 
  • Do open valves slowly to control pressure surges. 
  • Do crack the valve to remove dust in the thread before attaching a regulator. 
  • Do use the correct CGA fitting on regulators. 
  • Do have the TSSA inspect any gas lines that have greater than 45 psi. 
  • Do ensure adequate ventilation for the type of gas you are using. 
  • Do use flash arrestors on gas lines in all open flame equipment. Do check tubes and regulators for leaks.


  • Do not put oxidizing and flammable gases near each other. Oxygen should be segregated from hydrogen or propane. 
  • Do not use grease or oil on oxygen regulators. Oxygen gas lines must be approved for oxygen use. 
  • Do not change fitting on regulators. The CGA fitting is specific for gas type. 
  • Do not drag or slide cylinders or let them drop.
  • Do not try to refill cylinders. 
  • Do not expose cylinders to high temperatures. The cylinder may explode.
  • Do not use copper tubing with acetylene gas; explosive compounds may be formed.
  • Do not use compressed gas without a pressure reducing regulator. 
  • Do not bring a compressed gas cylinder within the 5 gauss line of a superconductor magnet.


Common Compressed Gases

Classification Examples
Flammable (Inflammable) Hydrogen, Acetylene, Propane
Inert Helium, Argon, Neon
Toxic Carbon Monoxide, Cyanogen , Hydrogen Sulphide
Corrosive Hydrogen Chloride, Chlorine, Hydrogen Fluoride