A University of Alberta building was evacuated after a chemical explosion in a room on Wednesday afternoon.

Edmonton Fire Rescue Services were called to the university’s Electrical and Computer Engineering Research building at 1:40 p.m., and arrived six minutes later.

Upon arrival, firefighters determined there had been a nitric acid explosion in one of the rooms and called their Hazmat crew.

Approximately 200 people were evacuated before firefighters arrived.

There were three people in the room where the explosion occurred, EFRS said, but they were wearing protective equipment and did not sustain injuries.

The building was re-opened at 4:15 p.m.