Show ZINC DUST FIRES at the pittsburgh pa experiment station of the bureau of mines tests were recently made with water sodium carbonate solution carbon tetrachloride silicon tetrachloride and a frothy mixture as extinguishers for zinc dust fires the frothy mixture extinguished the fire most quietly and effectively so it was tested on a larger fire in pounds of zinc dust three 2 gallon galion foam extinguishers smothered the fire but danger of rekindling kindling re had passed only after elapse of several hours due to retention of heat in the metal by the conducting non foam blanket thermal data show that water carbon tetrachloride and carbon dioxide react with zinc with libe liberation ratiA of considerable heat carbon tetrachloride producing most however no violent reaction occurred when red hot molten zinc was poured into carbon tetrachloride although some fire extin extinguishing 6 bishing materials may be injurious or may be decomposed in fires to produce toxic gases or vapors no especially poisonous gases or fumes are evolved from burning zinc itself or from the action of extinguisher material on the zinc |