Residents near the Chemours plant in Belle were asked to shelter in place after an explosion was reported in the area Tuesday night.
Those who live within a two mile radius are asked to stay indoors. The explosion was reported just after 10 p.m.
Four people were injured in the incident.
Officials believe a chlorinated dry bleach and methanol were the chemicals involved in the explosion.
Officials said the explosion happened in the Optima Chemical operations area of the plant.