Eight fire engines and around 60 firefighters tackled a flat fire on Rayleigh Road in Silvertown.
Most of a flat on the seventh floor of a 12 storey block was damaged by the fire. Around 80 people left the building before the Brigade arrived. There were no reports of any injuries.
The fire was extremely visible and the Brigade's 999 control took 34 calls to the blaze.
The Brigade was called at 0012 and the fire was under control by 0126. Fire crews from Plaistow, Millwall, East Ham, Stratford, Shadwell, East Greenwich, Whitechapel and Barking fire stations attended the scene.
The cause of the fire is accidental and fire investigators believe it was due to unsafe disposal of smoking materials. Fire officers believe the rapid spread of fire was contributed by exploding paint aerosol cans stored on the balcony.
London Fire Brigade spokesperson said:
"Aerosols can explode when exposed to fire and heat so they should be stored out of direct sunlight and not on balconies.
“Balcony fires can be devastating as they can easily spread to adjoining properties, potentially leaving many people homeless if the fire is serious enough.
“Many balconies have combustible materials as part of their construction and there are often combustible items stored in outside spaces so if a fire starts it can spread quickly.”