Edmonton Fire Rescue Services confirmed there was a suspicious package containing white powder found at the Canada Post office at 121 Avenue and 149 Street on Thursday morning.
Fire crews received a call from police at 10:28 a.m.
Four fire crews and two hazmat units were dispatched to the scene.
Some people exposed to the package have been quarantined, a fire spokesperson said. She could not say exactly how many people.
As of 11 a.m., no one was suffering any medical issues.
The building was evacuated as a precaution.
As of noon, emergency vehicles had left the scene.
Officials said the substance was powdered sugar.