SHERMAN, TX -- Crews were called out twice to battle flames at a manufacturing facility that makes insulation.

Fire crews were called to CertainTeed Insulation once again around 5:45 p.m. on Thursday. They had left the scene several hours earlier, after the fire first broke out around 6:20 a.m., causing the building to be evacuated.

The first time, when crews got there, they reported seeing flames from the roof of the building near the loading dock area.

Plant manager Anand Chowbey said there was a small fire in the filtering system, and according to the fire department, it was actually ground-up dust created in the process making the insulation that caught fire.

"This is a highly explosive material, a real fine dust, so it was pretty labor intensive to get in there and make sure everyone remained safe, that we kept the fire contained to the area of the plant that was affected," says Fire Chief Jeff Jones.

Jones says the fire was between the machine and a vent that goes to the roof. "The vent is much like a chimney flue in your own home, so many times you get an accumulation of resin or materials in those flue pipes, so any spark an overheated motor or fan or anything like that ignites. We believe that's what happened," Jones says.

About 40 firefighters including units from Howe and Whitesboro responded to the fire. "This is interior of an industrial complex so everybody had to wear their breathing apparatus and rotating those crews in and out," Jones says.

Jones says the fire caused around $200,000 damage including lost production time, and just a small spark may have been enough to ignite the dust. 

A sign at the entrance of the plant says it has been six years since a major accident. Workers were assessing the damage caused by the fire to determine when it can begin running again. No one was injured in the fire.