Seven fire engines tackled the blaze at Recycling Lives’ Longridge Road site.
With smoke plumes billowing into the air, Lancashire Fire and Rescue service had urged residents living nearby to keep their windows and doors closed.
Longridge Road remains closed this morning and part of the Guild Wheel is also closed.
Station manager Matt Armstrong said: “The fire was really ferocious. It needed a lot of resources in the initial stages.
“We’re still advising members of the public to keep their doors and windows shut.
"The smoke plumes have disappeared but we are still getting flare ups when we’re turning things over.
“We’re reducing resources now - we’ve got five fire engines down here.
“The fire investigation team will be down here this morning.
“But our priority at the moment is just to get the fire out.”
The fire which started just before 10.20pm on Friday saw seven fire engines blue light to the blaze.
The Fire Service said the site of the blaze measured 50m x 50m and “mainly involving recycling material from road vehicles”.
Preston Police said: "Lancashire Fire and Rescue is still dealing with an incident on Longridge Road near to Redscar and Roman Way Industrial Estate.
"Due to this incident Longridge Road is closed in both directions in this area and also the Guild Wheel."