Firefighters attending a fire at a recycling plant in Derbyshire said it could take up to three days to put out.
About 8,000 tonnes of wood and sawdust at the centre in Lows Lane in Stanton-by-Dale, near Ilkeston, started burning on Saturday night.
The fire caused thick black smoke to drift across the M1, causing problems on Sunday.
Station manager Gary Platts, from Derbyshire Fire and Rescue, said it had been a difficult fire to control.
He said: "Unfortunately because the wind [was] against us, and the way the wood was stored in the yard, it's been very difficult to access the whole perimeter of the fire so it could last two, three or several days."
Junctions 25 and 26 of the M1 were affected on Sunday but firefighters said there should not be problems on Monday.
The fire service also said there was no danger for residents from the smoke fumes.