Four fire engines and around 25 firefighters were called to a disused caravan fire at Keston Mobile Park on Layhams Road, in Keston.
Watch Manager Dan Oldacre, who was at the scene, said: "A neighbour saw flames and immediately called 999. Crews removed one acetylene cylinder and cooled it to ambient temperature as gas cylinders can explode when exposed to heat."
The disused caravan was destroyed by fire.
The Brigade was called at 2001 and the fire was under control at 2330. Fire crews from Biggin Hill, Addington, and Woodside fire stations attended the scene. The cause of the fire is under investigation.