Firefighters have put out a fire that started from a gas cylinder at a Weston dentistry on Thursday afternoon.

The Emergency Services Agency said ACT Fire & Rescue was ventilating the two-storey building on Brierly Street, Weston after it caused minimal damage to RFG Dentistry.

"Occupants utilised a fire blanket to cover the gas cylinder and safely self evacuated before ACT Fire & Rescue crews extinguished the fire," the agency said in a statement.