Carbon Monoxide Exposure Results in 6 Transported to Hospital

Location: North Vancouver

Regulated industry sector: Gas

Incident overview

In North Vancouver, six residents of a multi-unit apartment building were transported to hospital for treatment of carbon monoxide (CO) poisoning after a heating boiler’s vent became disconnected, allowing exhaust gases containing CO to enter the building. 

Our investigation found that a delayed ignition likely produced enough force to disconnect the boiler’s vent. The boiler continued to operate with the vent disconnected, allowing flue gases to spill into the mechanical room and migrate through unsealed openings into occupied areas of the building. Recirculation of the flue gases also caused incomplete combustion, significantly increasing CO production. 

There were no operating CO alarms in the building, allowing the exposure to continue undetected as CO levels increased. Without a resident looking up the symptoms online and recognizing it could potentially be CO, the exposure could have continued, potentially resulting in a more serious incident. Emergency responders were alerted, and the building was evacuated and the boilers shut down. Six residents were transported to hospital for treatment.