Compressed gases are gases contained in a receptacle under pressure. Compressed gases are stored in heavy-walled metal cylinders designed, produced, and tested for use with pressurized compressed gases. Cylinders are made in a wide variety of sizes and shapes. Common compressed medical gases include propane, oxygen, Helium, Hydrogen, Argon, Nitrogen, carbon Dioxide, and Acetylene.
Associated Hazards: Compressed gas cylinders present a variety of hazards due to their pressure and/or their content. Depending on the particular gas, there is also potential simultaneous exposure to both mechanical and chemical hazards. Compressed gases may be flammable or combustible, explosive, corrosive, acidic, reactive, toxic, and inert.
Physical Hazards: Compressed gas cylinders have very high internal pressures, in some cases up to 2,500 psi. Exposing these cylinders to heat, knocking them over, or allowing them to become part of an electric circuit can contribute to weakness in the cylinder wall or damage to the valve. Such careless actions or damage can cause:
- The cylinder to tip over onto the user causing a contusion or crushing injury.
- The cylinder wall ruptures and explodes, sending metal shrapnel flying into the air.
- The valve becomes broken off, rapidly releasing all of the gas contents and possibly spinning out of control or actually becoming airborne.
Content Hazards: Each compressed gas cylinder has unique hazards based on its contents. An incident involving the release of flammable, corrosive, explosive, toxic, or a combination of these gases could cause harm to human health. Some gases are inert, but do not confuse this with being “safe!” Depending on the gas or mixture of gases, an accidental release or leak from a cylinder could cause:
- Burns or frostbite from contact with rapidly expanding gases
- Suffocation (asphyxiation) or death
- Chemical poisoning from toxic gases
- Damage to certain target organs
- Exacerbation of pre-existing health problems
- An increased risk of fire and may aid combustion
- Destruction of skin and mucous membranes
When regulated, such as under WHMIS 2015- SDS (Safety Data Sheets), compressed gases will be labelled with a “gas cylinder” pictogram on the label. This symbol indicates that hazardous products with this pictogram are gases that are contained in a receptacle under pressure, or which are liquefied or liquefied and refrigerated. The hazards presented by these products are related to the high pressure or cold temperatures. Hazardous products with this pictogram can be safely worked with if proper storage and handling practices are followed.
Safe work instructions should be included on the Safety Data Sheet (SDS). Compressed gases are considered dangerous goods under the federally regulated Transportation of Dangerous Goods (TDG) Act and also in the provincially regulated Dangerous Goods (Transportation) Act (in Schedule 1) as class 2 Gases (compressed, deeply refrigerated, liquefied or dissolved under pressure).
What should you do in case of an emergency if you are someone who stores, handles and transports compressed gases?
- Understand and practice emergency procedures so that you know what to do if it becomes necessary.
- Ensure that eyewash and an emergency shower are readily available in the immediate work area. (These devices are tested regularly by the Facilities Department.)
- Do not drop or bang cylinders against each other. Move cylinders using a hand truck or cart designed for the purpose.
- Secure the cylinders to a wall or rack in an upright position. Leave the cylinder cap in place until the cylinder is secured and ready to use.
- Immediately report leaks to your supervisor and follow the code brown protocol if necessary.
- Follow by-laws and regulations, such as building fire codes and health and safety regulations, that apply to the workplace in your jurisdiction.
If you notice any unsafe acts or safety noncompliance, please put in an IRIS report immediately. If you have any concerns or questions, please contact Abinaya Selvakumar (Aby), Occupational Health and Safety Specialist @abinaya.selvakumar@wchospital.ca