Six people are in hospital after being exposed to noxious fumes at a fitness centre in Etobicoke, Ont., on Saturday afternoon.

Emergency crews were called to the Goodlife Fitness facility at 185 The West Mall shortly after 3 p.m., where they evacuated 45 people from the building.

Toronto EMS commander Peter Rotolo said that crews treated 25 people, mostly with minor inhalation troubles, and cleared 19 of them at the scene.

The remaining six people were sent to hospital, where one is being treated for serious injuries.

According to Rotolo, the patients were exposed to chlorine gas fumes from a pool in the facility, where chemicals were "improperly mixed," creating a toxic effect.

The building has been cleared for re-entry by emergency crews, Rotolo said, but the Goodlife Fitness centre is closed for the day.