Abstract: An employer manufactured explosive compounds by recrystallizing a batch containing approximately 50 pounds of material. Mixing and manufacturing usually took place in a single vessel. Employee #1 placed the first powdered component into the vessel. Employee #1 then began to introduce the acid into the vessel. Employee #1 went to a nearby structure to speak with Employee #2. Employee #1 heard a brief hiss, and the vessel exploded. Employee #2 suffered burns to his back and was admitted at a local medical facility for treatment. Employees #1 and #3 developed hearing loss. At the time of the explosion, approximately 60 gallons of acid had been charged into the vessel (half of the total). A fire began shortly thereafter. The surrounding structures and all materials were burned from the fire. An emergency response team responded to the incident. The emergency response team allowed all the materials to be consumed by the fire.