Eight fire engines and around 60 firefighters were called to a fire at an industrial estate on Hainault Road in Romford.
The ground floor of a two-storey industrial unit was destroyed by fire. There were no reports of any injuries.
The Brigade's 999 Control Officers took nine calls to the fire.
The Brigade was called at 2056 and the fire was under control by 0002 (Thursday). Fire crews from Wennington, Dagenham, Romford, Hornchurch, Ilford and surrounding fire stations were at the scene.
The cause of the fire is under investigation.