Abstract: At 3:15 p.m. on October 13, 2018, an employee was working for a firm that manufactured materials from natural fibers. He was working in Building 4 as a shift leader. He was operating a Herbold Meckesheim mill. He was milling wood fiber to powder form. Specifically, he was milling a blend of three different wood fibers to develop TC-150, a technical non-food-grade hardwood powder. The blend of fibers consisted of Alabama River hardwood, American Fiber, and International Paper Eastover hardwood. During the milling process, the employee determined that the 200-mesh/2.5 micron sieve on the Herbold Meckesheim mill was beginning to blind. If this continued, the mill would clog. The employee shut down down the mill, released the clamps against the cutting blades, and opened the door to the mill. As the employee opened the door to inspect the blinding, a flash fire occurred. The fire went to the dust collection filter bank, setting the filter socks on fire, rupturing the explosion disks, and being exhausted outside through the explosion venting. The employee was thrown back approximately 2 meters (79 inches). He was taken to the hospital as a precautionary measure. He was hospitalized. The employee later returned to work with no restrictions.