Four fire engines and around 25 firefighters attended a fire on Jeymer Drive in Greenford.
A garden shed situated in a rear garden was destroyed by fire. Firefighters cooled two gas cylinders to an ambient temperature, as some cylinders can explode when exposed to heat.
There were no reports of any injuries.
The Brigade received the first of 15 calls at 1858 and Control Officers mobilised crews from Northolt and Southall fire stations to the scene. The fire was extinguished by 2000.