Fire crews are battling a blaze at the Chadwell Heath industrial park.
Around 150 firefighters and 25 fire engines are at the scene on Kemp Road in Dagenham, where half of a single storey car repair workshop is alight.
Station Commander Barrie May, who is at the scene, says it will be a "protracted" incident.
He said: "Local residents are advised to keep windows and doors shut as there is heavy smoke in the area."
London Fire Brigade's 999 control centre has received 73 calls about the blaze.
The brigade was first called at 8.27am.
Crews from Dagenham, Ilford, Romford, Hornchurch, Hainault, East Ham, Barking, Walthamstow, Harold Hill, Stratford, Plaistow, Wennington, Leytonstone and surrounding stations are on scene.
The cause of the fire is not known at this stage.
It follows another blaze at the industrial estate last Saturday night, January 18.
The brigade was called at 10.47pm to the fire, which damaged a number of workshops and destroyed three vehicles inside a car repair workshop.
There were no reported injuries.
Firefighters cooled three gas cylinders to an ambient temperature and removed them as some cylinders can explode when exposed to heat.
Crews from Dagenham, Barking, Ilford, Romford and Hornchurch stations were at the scene and had the fire under control by 12.52am.
The cause of that fire is under investigation.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here