Fifteen fire engines and around 100 firefighters were called to a fire at an industrial dry cleaning unit on Raven Road in South Woodford.
Most of the first floor and part of the ground floor of the two-storey building were damaged by the fire. There were no reports of any injuries.
Firefighters cooled a gas cylinder to an ambient temperature and removed it as cylinders can explode when exposed to heat.
Station Commander Paul Green, who was at the scene, said: "Firefighters worked hard to bring this significant blaze under control.
"Due to the nature of the business, there were a lot of materials including bed linen and towels inside which caught alight.
"The fire created a lot of thick smoke so we asked local residents to keep windows and doors closed."
The Brigade's 999 Control Officers took 15 calls to the blaze.
The Brigade was called at 2156 and the fire was under control by 0134 (Tuesday). Fire crews from Woodford, Leytonstone, Walthamstow, Chingford, Hainault and surrounding fire stations were at the scene.
The cause of the fire is under investigation.