What is the potential risk?

With COVID-19 vaccinations underway in B.C., there is a potential risk to workers associated with dry ice used to keep vaccines cold during transport and storage.

Dry ice is solid carbon dioxide (CO₂). This material changes directly from a solid to a gas phase at room temperature and pressures, giving off carbon dioxide gas.

Carbon dioxide gas is colourless and odourless. It is heavier than air and will settle in low areas. This can result in significant displacement of breathable air, especially in small, poorly ventilated, and enclosed spaces.

Exposure to carbon dioxide can affect a worker’s health in different ways. Symptoms of carbon dioxide exposure depend on the level of concentration, and can include the following:

Dry ice can also cause severe frostbite or chemical burns if a worker’s skin comes into contact with the ice or even the packages that contain it. This can result in serious tissue damage if first aid is not conducted properly.

Dry ice can present an explosion hazard if the packaging does not allow the carbon dioxide gas to escape. The buildup of carbon dioxide in the package creates excessive pressure energy that may be suddenly released by rupturing of the package material.

Who is at risk?

Workers may be at risk if they handle packages that contain dry ice. This could include workers in shipping and receiving, delivery workers, and others who may come into contact with the packages. Risks are increased if workers are handling these packages in enclosed spaces with poor ventilation, such as transport compartments in aircraft and other vehicles, storage areas, or walk-in coolers.

How can I reduce the risk in my workplace?

Only handle dry ice packages in well-ventilated areas. A package of dry ice gives off 0.2 kg per hour of carbon dioxide (for a package containing 2.3 kg of dry ice pellets). You may need to add ventilation fans and/or air movers to rooms or other enclosed spaces such as vehicles used to transport the packages. If there is any doubt about the ventilation in an enclosed area, the atmosphere must be tested for oxygen and carbon dioxide by a qualified person.

Develop safe work procedures for handling and storing dry ice. Make sure workers are trained in these procedures. Examples of procedures include the following:

• Store dry ice in well-ventilated areas.
• Do not store in airtight rooms, containers, or enclosures.
• Make sure there is a supply of fresh air when transporting dry ice in vehicles.
• Wear safety glasses and thermal gloves when handling packages to prevent eye and skin burns.
• Dispose of dry ice safely by opening the container and leaving it in a well-ventilated area at room temperature.
• Avoid subjecting containers that contain dry ice to extreme temperatures.
• Move containers that contain dry ice with care.

Train workers on the signs and symptoms of carbon dioxide exposure and what to do if they are exposed:

• If you feel short of breath or develop a headache, these may be signs that you have inhaled too much carbon dioxide.
• Leave the area immediately and move to an area with fresh air.
• Report to first aid.

Where can I find more information?

• Part 5 of the Occupational Health and Safety Regulation, and related Guidelines
• WHMIS (Workplace Hazardous Materials Information System)
• Hazards & exposures - Carbon dioxide
• Guidance for Receiving and Handling the Pfizer-BioNTech COVID-19 mRNA Vaccine (including dry ice procedures) (BC Centre for Disease Control)

Learn more about managing risk in your workplace.