Cutting and welding processes using electric arcs or oxy-fuel gas flames are necessary for our industrial world. Too often, however, the persons who use, hire, or supervise the use of the processes do not fully appreciate that their improper use can result in the loss of life and property by fire and explosion. Approximately 6 percent of fires in industrial properties have been caused by cutting and welding, primarily with portable equipment in areas not specifically designed or approved for such work. Cutting and welding operations produce thousands of ignition sources in the form of sparks and hot slag. The electric arc, the oxy-fuel gas flame, and the hot work pieces are inherent ignition sources. Sparks have caused most industrial fires in which cutting and welding are a factor. These globules of molten metal have scattered as far as 35 feet, setting fire to all kinds of combustible materials. They have also fallen through cracks, pipe holes, or other small openings in floors and partitions, starting fires that have reached serious proportions before being noticed.