Abstract: Employees #1 through #11, all firemen, responded to a blaze at a finishing plant that was closed for the weekend. They found a smoking storage building and began to fight the fire, believing it to be structural. The firemen suited up, entered the building, and had begun pouring water on the fire when they found several chemical drums. One of the employees pulled a label from one of the drums, took it outside, and had it checked in their computer system. According to the label, the drums contained sodium hydrosulfate, a water-reactive, flammable solid. All the firemen were called out of the building and the area secured. Some of the firemen that first entered the building complained of nausea and a burning sensation in their respiratory tracts. As a precautionary measure, Employees #1 through #11 were sent to the emergency room for an examination.