Ten fire engines and around 70 firefighters tackled a fire at an industrial estate on Church Road in Heston.
One unit at the industrial estate used for commercial laundry was destroyed by fire. A small area of two further units was damaged. There were no reports of any injuries.
The Brigade's Fire Investigators believe the fire was caused by the self-heating of tea towels that had been contaminated with oils.
A London Fire Brigade spokesperson said: “These types of fires often involve textiles that become contaminated with oil, most commonly linseed, massage and cooking oil on tea towels, tablecloths and chef whites.
"Sometimes when materials are cleaned, put in tumble dryers and then folded and stacked, the heat from the tumble drying cannot escape. This can result in a high enough temperature allowing it to build up to a point where it smoulders and eventually ignites.
“If you are washing and then drying on a hot cycle, always use the cooling cycle on the tumble dryer so it cools down and allow the heat to dissipate properly, before stacking laundered items together.”
The Brigade was called at 0201 and the fire was under control by 0636. Fire crews from Heston, Southall, Feltham, Hayes and Kingston fire stations attended the scene.