Carbon Monoxide
Annual State of Safety 2024
Carbon Monoxide: A Preventable Danger
Carbon monoxide (CO) is often called the "silent killer" — and for good reason. It's colorless, odorless, and impossible to detect without a CO alarm. Every year, people across BC are exposed to CO, sometimes with deadly consequences. In 2024, carbon monoxide exposure once again tops Technical Safety BC's list of the most significant safety risks.
CO is an odorless, tasteless, and invisible gas that is produced when fuels like propane, natural gas, oil, charcoal, or wood are burned incompletely. Because CO cannot be detected without an alarm, it is extremely dangerous. When inhaled, CO interferes with the body's ability to absorb oxygen and can cause symptoms ranging from headaches and nausea to unconsciousness and death.
Although CO exposure can be deadly, it can be prevented by installing CO alarms and hiring licensed contractors to perform regular maintenance on your gas appliances.
Findings From Our Carbon Monoxide Risk Analysis
Over the past five years, we saw an average of 15 CO-related incidents, 24 injuries, and two fatalities reported annually. Residential properties account for 80% of these incidents, with single-detached homes accounting for 65%. CO exposure has also been reported in a variety of non-residential settings, including ice rinks, warehouses, and schools.
Our 2024 risk analysis identified several key factors contributing to CO exposure. In addition to poor maintenance of gas-fired equipment, factors include:
- incorrect installation of venting and air supply;
- misuse of equipment (such as using outdoor heaters indoors); and
- bypassing safety features.
These findings highlight the importance of hiring a qualified individual for installation and maintenance.
We also found that the risk of CO exposure can increase when updates or alterations are made that affect a building's air pressure and airflow. Adding appliances like portable air conditioners, kitchen exhaust fans, or air-sealing doors and windows, can unintentionally affect airflow and increase the risk of CO buildup. When these changes are made, homeowners should engage a licensed contractor to reassess the home's air pressure balance and adjust fuel burning appliance exhaust settings as needed.
In 2024, we investigated two incidents involving CO exposure which resulted in injuries, the tragic loss of a family pet, and the evacuation of an animal shelter. The ongoing occurrence of CO exposure and the severity of the incidents we've investigated demonstrate the importance of public education on prevention, detection, and response.
Animal Shelter Staff and Animals Exposed to CO
In January 2024, the staff and animals at an animal shelter in Maple Ridge evacuated their building after experiencing symptoms of CO poisoning, including headaches and dizziness.
Our investigation found that qualified technicians had removed the condensate trap from the shelter’s boiler during a troubleshooting event, which caused flue gases to enter the mechanical room and spread into other rooms of the building through a filter gap in the air handling unit.
Although no animals were harmed, eight staff members experienced carbon monoxide symptoms. The absence of CO alarms in the shelter delayed early detection of the gas, emphasizing a major safety gap in public and shared spaces.
A Clogged Boiler Vent Leads to the Death of a Family Pet
In February 2024, a homeowner in Smithers, BC, tragically discovered their pet deceased near the mechanical room of their home. The homeowner had been experiencing headaches and fatigue for months without realizing they were being poisoned by CO leaking from a neglected boiler. Investigators found the boiler’s heat exchanger and vent clogged with soot due to years of incomplete combustion.
Without a functional CO alarm, the homeowner had no way of detecting the gas accumulating in their home. This incident reiterates the importance of having all gas appliances serviced regularly and ensuring CO alarms are installed and maintained on every level of the home.
In both incidents, our investigations found that CO exposure could have been prevented through proper appliance maintenance and early detection provided by CO alarms.
Raising Awareness About CO and Protecting Pets
Each year, we run a public safety campaign to raise awareness about the risk of carbon monoxide exposure, focusing on prevention, detection, and response. This campaign aims to educate British Columbians on how to protect themselves and their families from CO exposure. Our campaign uses a combination of traditional and digital media channels including social media, radio ads, bus and SkyTrain ads, community partnerships, and a press release.
With two CO incidents in 2024 involving animals, and one even resulting in the tragic loss of a family pet, we adjusted our fall carbon monoxide awareness campaign to stress the importance of protecting the entire household, including pets, from CO exposure. This year we strengthened our pet messaging by partnering with the BC SPCA, who helped us extend our reach and allowed us to tailor our messaging to emphasize the risk CO poses to both people and pets.
Looking Ahead: Our Commitment to CO Safety
While the number of incidents investigated in 2024 was lower than the previous year, the risk associated with CO remains significant. Moving forward, we will take a multi-pronged approach to reducing CO-related incidents across BC with risk mitigation efforts that:
- leverage all core functions of Technical Safety BC, including codes and regulations, inspections, research, and public education; and
- address the needs of vulnerable groups identified in our analysis.
For example, CO incidents are more prevalent in linguistically and racially diverse neighbourhoods. Areas with higher concentrations of low-income households, rental homes, and those experiencing housing insecurity see increased incidents associated with inadequate maintenance and incorrect venting installation. Remote communities are found to have higher rate of CO exposure incidents associated with incorrect appliance use, and gas-fired equipment being installed without proper venting or air-supply — often with more severe consequences.
By implementing system-wide improvements and delivering targeted public safety education to these groups, we are committed to reducing CO-related incidents across BC and supporting the safety of all communities.