Union County Emergency Management Director Curt Clayton said in a news release Wednesday that two workers escaped without injuries at the time of the explosion around 6:00 a.m.
Officials planned to let the fire at North Mississippi Biodiesel burn out because it was too hot to fight, according to Mississippi Highway Patrol spokesman Ronny Hall.
The Mississippi Emergency Management Agency said one home and two industrial businesses near the plant were evacuated as a precaution.
MEMA said the Mississippi Department of Environmental Quality has teams in the area to test for hazardous materials that may leave the site, but have not detected any so far.
The explosion also damaged a nearby power substation that caused a power outage to the town of Blue Mountain and surrounding areas in Tippah County, including Blue Mountain College. The electricity was restored, MEMA said.
David L. Franks, listed as North Mississippi Biodiesel's vice president in documents filed with the Mississippi Secretary of State's office, declined to answer any questions when contacted Wednesday by The Associated Press. The company was incorporated in 2005, according to secretary of state's office records.
Phil Nanney, executive director of the Union County Development Association, said the business is "relatively small operation" with about five employees. He said a church daycare center near the plant asked parents to keep their children home Wednesday as a precaution.
"A large plume of smoke could be seen from several miles away," Nanney said in a telephone interview.
The plant is located in northeast Mississippi, near New Albany, a town of about 8,000 people, on Highway 15, which remained closed to traffic on Wednesday afternoon.