Around 60 firefighters and officers dealt with a fire at an industrial estate off Kemp Road in Dagenham.
An industrial unit was alight.
8 fire engines and two aerial ladder platforms from stations including Dagenham, Barking, Havering and Hornchurch Fire Station were at the scene.
The Brigade was called at 2213 and the fire was under control at 0013 although firefighters will be damping down hotspots for some time.