Four fire engines and around 25 firefighters tackled a fire in an open-air storage area on Renwick Road in Barking.
A stack of cardboard on wooden pallets was destroyed by fire. An excavator and thermal imaging cameras were used to identify and access seats of fire. There were no reports of any injuries.
The Brigade was called at 0510 and the fire was under control by 0632. Fire crews from Barking, East Ham and Ilford fire stations attended the scene.
The cause of the fire is under investigation.