Danville firefighters battled a blaze at Blue Ridge Fiberboard on Saturday afternoon at 250 Celotex Drive in Danville.
The fire was reported just before 1 p.m. and occurred in a staging area containing fiberboard stacked on pallets.
As firefighters doused the flames, the thick, black smoke â€” visible for miles â€” turned gray and white.
It was the second fire at the plant in about two weeks. A fire there on May 30 damaged a large quantity of finished goods.
Fire personnel spent more than four hours that day getting the fire under control and making sure it had not extended into the structure, according to the fire department.
The cause of the May 30 fire was determined to be spontaneous combustion due to the heat required to cure the product and it being tightly packed, according to the fire department.
Blue Ridge Fiberboard makes roofing products, soundproofing materials and exterior sheathing products, according to its website.
Danville Fire Department Capt. Barry Neal said about 19 personnel, four engines and two aerials responded to Saturdayâ€™s fire. Crews contained the fire in about 30 minutes but firefighters were still on the scene at 7 p.m., wetting down material to make sure is didnâ€™t re-ignite.
No one was injured.
The cause of the fire is unknown and the incident is under investigation, Neal said.