Fifteen fire engines and around 100 firefighters were called to a fire at an industrial laundrette and warehouse on Selinas Lane in Dagenham.
Most of the ground and first floors of a two-storey warehouse were damaged by fire and half of the roof was also damaged by the blaze. There were no reports of any injuries.
The fire was discovered by a member of staff working opposite the site who heard an alarm and a bang and saw a glow from the roof. He then made the first call to the Brigade.
Station Commander Paul Eastland said: "Firefighters wearing breathing apparatus worked incredibly hard at the scene of a warehouse fire.
"The fire appears to have started on the ground floor of a laundrette and crews swiftly gained access and worked to bring the fire under control.
"Crews removed gas cylinders as a precaution, as some cylinders can explode when exposed to heat.
"Road closures were in place whilst firefighters made the scene safe."
The Brigade's 999 Control Officers took 25 calls to the fire.
The Brigade's Fire Investigators believe the fire was accidental and caused by self-heating linen that was contaminated with oil and had recently been laundered, dried and stacked.
These types of fires often involve textiles that become contaminated with oil like linseed, massage and cooking oil. Sometimes when materials are cleaned and put in tumble dryers, 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. Make sure you also check the manufacturers cleaning recommendations of your textiles before washing.
The Brigade was called at 2359 and the fire was under control by 0221. Fire crews from Dagenham, Ilford, Romford, Barking and surrounding fire stations attended the scene.