It was cornstarch inside a suspicious package that led to the quarantine of nearly two dozen people at the Calgary Courts Centre Thursday.
Just before noon, a call came into 911 about an envelope containing a white substance found on the eighth floor.
The fire department quarantined 22 people because some reported feeling a mild irritation, but no one was in medical distress.
The floors above and below were evacuated as a precaution and the ventilation system in the building was temporarily shut off.
The Calgary Fire Department’s hazardous materials unit tested the powder, which turned out to be cornstarch.
“We have very strict protocol on these white-powder calls,” Calgary Fire Department spokesperson Carol Henke said.
“They were a lot more common after 9/11 and we still get them from time to time.”
Two hours later, the fire department gave the all-clear.
Police are investigating where the package came from and the circumstances that led to the situation.
With files from Global’s Ken MacGillivray