Abstract: Employee #1, a crane operator at the R. Freedman & Son, Inc., scrap yard in Green Island, NY, placed a station wagon, a refrigerator, and an acetylene cylinder in an American Pulverizer Company Hammermill pre-ripper machine, serial #8062. The material exploded and a fire broke out in the machine. The cab door of the crane blew out and Employee #1 sustained a temporary ringing in his ears. The Green Island Fire Department and police responded to the explosion. One of the firemen who extinguished the fire stated that he saw what was apparently the remains of a 100 lb propane cylinder. The police reported that 40 windows in the company next door had been blown out. It was a routine procedure for this scrap yard to destroy propane and acetylene tanks, but they did not correctly prepare the cylinders for destruction. The company procedure was to vent the cylinders for 24 hours and to remove the valves prior to placing them in the pre-ripper machine or in the American Pulverizer Company's shredder machine, serial #66X90. In the case of acetylene cylinders, they would sometimes shear them with a Volvo trackhoe shredder attachment. The Compressed Gas Association and the National Propane Gas Association guidelines require that gas cylinders be purged after venting and before they are destroyed. Purging is done with an inert gas, water, or steam. Furthermore, the instruction manuals for both machines prohibited the placing of combustibles, liquid or gaseous fuels, and other substances that could cause explosions into the machines. Regarding acetylene cylinders, they were required to be burned in an intense fire for at least six hours prior to further destruction. Both of the Associations recommended that scrap yards NOT destroy compressed gas cylinders, and that it be done by qualified and trained individuals, manufacturers, or distributors of compressed gases.