Up to 20 firefighters tackled a blaze at a recycling centre in Wellingborough.
Crews were called to F&R Cawley on the Finedon Road industrial estate just before 7am yesterday (Wednesday).
A spokesman for the fire service said a quantity of household waste was involved in the fire.
Firefighters worked with staff at the site, in Nielson Road, to bring the blaze under control and stop it spreading.
People living nearby and businesses in the area were advised to close their windows in case smoke from the fire was blown towards their properties.
Smoke can still be seen coming from the site today (Thursday).
The cause of the fire is not yet known.