Four fire engines and 21 firefighters were called to a fire at a bakery with flats above in Leeland Road, Ealing.
There was a small blaze in a ceiling cavity between the ground and first floors of the building and half of the ducting was damaged.
Three people left the building before the arrival of the Brigade.
The Brigade was called at 1126 and the fire was under control at 1306. Fire crews from Ealing, Acton, Southall and Hammersmith fire stations attended the scene.
The cause of the fire is not known at this stage.