Tunney’s Pasture government building evacuated after toxic gas leak

Hazmat crews at the scene of a gas leak at the Sir Frederick Banting Building in Ottawa on Tuesday, June 17, 2025. (Jean Lalonde/Ottawa Fire Services)

A federal government building in Tunney’s Pasture had to be evacuated because of a toxic gas leak Tuesday afternoon.

Ottawa Fire Services spokesperson Nick Defazio tells CTV News Ottawa that a hazmat team was called to the Sir Frederick Banting Building, which houses Health Canada workers, at approximately 12:08 p.m.

Defazio says an investigation found phosgene gas was leaking from a compressor inside.

Ottawa paramedics spokesperson Marc-Antoine Deschamps tells CTV News that 10 people were assessed at the scene but no one was taken to hospital. It’s unclear how many workers were inside the building at the time.

Health Canada says in statement to CTV News Ottawa that medical assistance was offered on-site, with “a number of people” being possibly exposed.

“While there were no immediate concerning health symptoms, these individuals were asked to continue to monitor for any reactions. Anyone who suspects that they may have been exposed to the gas should seek immediate medical attention,” a Health Canada spokesperson said in an email.

The building management evacuated all workers before hazmat crews arrived on scene and were able to shut off the compressor, Defazio says.

Firefighters conducted two full searches of the building and found no one inside.

Air quality readings returned to normal before hazmat teams were able to clear the scene.

The building remained closed on Tuesday.

In an update Wednesday, Health Canada said it was able to reopen it following a thorough investigation with the exception of one corridor where a residual odour was still present.

Phosgene is a colourless and nonflammable gas that has the odour of fresh hay. It is highly toxic at elevated levels.

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