Abstract: At 7:45 a.m. on October 18, 2001, there were no employees working on the pre-sort, red belt line, where the accident occurred. A partially damaged box containing a powdered mixture of antibacterial agents used in agricultural feed crashed into another package at the end of the red conveyor belt in the pre-sort area of the facility. Employee #1, a regular part-time employee, standing at the end of the conveyor belt was exposed to a puff of fine powdery dust released by the damaged box. When he attempted to transport it to the damaged package processing area, his immune system elicited an immediate allergic response to the veterinary antibacterial agents ocinoxin and nalidixic acid contained in the powder. Employee #1 had no knowledge that he was allergic to these veterinary antibiotics. The package was handled as non-hazardous material because neither the manufacturer nor the shipper had identified it as a hazardous material. The subjective immediate adverse health effects reported by Employee #1 included swelling of the throat, bronchial constriction, nausea, vomiting, chest pain with tightness, weakness, and near syncope. Employee #1 was transported by ambulance to the emergency room of University Medical Center in Fresno. The objective clinical findings and diagnosis of Employee #1 included a slightly pale skin and respiratory distress; culminating in anaphylaxis as a consequence of inhalation exposure to agricultural antibiotics.