Four fire engines and around 20 firefighters and officers were called to a fire in a shed at a business park in Access Road, Uxbridge.
A shed was completely damaged by fire. One 19kg propane cylinder was removed by fire crews and cooled to an ambient temperature.
The Brigade was called at 1719 and the fire was under control at 1748. Fire crews from Hillingdon, Hayes and Heathrow fire stations attended the scene.
The cause of the fire is under investigation.