Part of a single-storey car workshop at the rear of a parade of shops was damaged by fire and two cars were destroyed by the blaze.
The fire was discovered by a member of the public who saw smoke coming from the industrial units. They then made the first of 14 calls to 999.
Firefighters carried out a search of the premises to make sure that everybody was out of the building. Around 30 people left a business centre before the Brigade arrived. Road closures were in place whilst crews worked to make the scene safe.
The Brigade was called at 8.48pm and the fire was under control by 10.20pm. Fire crews from Leytonstone, East Ham, Barking, Plaistow and surrounding fire stations attended the scene.
The fire is under investigation by the Brigade and the Metropolitan Police Service.