A plume of grayish-brown smoke was billowing from the Houston-based Multi-Chem Corp. plant Tuesday.
Despite the blast and fire, emergency officials say no one was injured. They say the first explosion came about 4 p.m. and several blasts followed. All workers at the facility are accounted for.
State police spokesman Stephen Hammons says teams have not determined what chemicals were burning inside a warehouse.
The building was next to the Acadiana Regional Airport, which was ordered to close.
Hammons says firefighters decided it was safest to let the fire burn itself out in the city about 75 miles west of New Orleans.