Firefighters were called to a blaze on derelict land in Wadsworth Road, Perivale on Saturday afternoon.
The fire involved approximately three tonnes of waste and caused a fire extinguisher to explode.
Firefighters cooled and removed another fire extinguisher from the scene and a 50 kilogramme propane cylinder, which was not involved in the fire, was moved to safety.
The Brigade was called at 1545 and the fire was under control at 1740. Crews from Ealing, Wembley and Northolt fire stations attended the scene.
The cause of the fire is under investigation.