Four fire engines and around 25 firefighters were called to a fire at a shop with flats above on York Street in Twickenham.
Part of the ground floor of a shop was damaged by fire. There were no reports of any injuries.
The Brigade's Fire Investigators believe the fire was caused by self-heating textiles. Oil used to treat wooden surfaces was left on a cloth which then overheated and self ignited.
A London Fire Brigade spokesperson said: "Natural fibres, such as cotton found in cloths, are susceptible to spontaneous heating and self-combustion. When this is mixed with materials such as oils or cleaning products, the likelihood of a fire increases as temperatures can build up to a point where the material smoulders and eventually ignites.
"When using oils and cleaning products with cloths, make sure you wash them at the right temperature with the appropriate detergent to remove any oil based contaminants. Also make sure you wait for your laundry to cool down before packing it away and store it in a well ventilated place.”
The Brigade was called at 2344 and the fire was under control by 0040. Fire crews from Twickenham, Richmond and Heston fire stations attended the scene.