Document emeX2LvJM0KZ0pZzQBxEyb1Kp

-38- and the demolition of process equipment and works structures. It also plays an important part in emergency and rescue work. Goggles with shade #5 i!oviweld lens are provided and their use is required. At the larger plants men with an average service credit of six years spend about three-fourths of their working time on cutting or burning operations (about half their time is given to "burning steel" for new construction). The amount of dust pro duced is usually greater than that caused by oxy-acetylene welding. DUST PRODUCED BY 0XY-ACETYLE1S BURNING Material Being Particles Characteristics of Dust Particles Burned Tip Used per cu. ft. (Sizes and Percentages Estimated) Burning 6" Flues (1-1/2" thick) Out of Shell Still. Oxweld #2 1,869,120 About 75# round blaok, 2 microns or less in size; 20# slightly angular, crystalline, 2 microns or less; 5# opaque, scale-like, various sizes. 1/2" Boiler Plate (soft steel) Oxweld #4 2,718,720 About 9C# semi-opaque, black, 2 microns or less 10# round, dark grey, over 5 microns in size. 2. WITH NATURAL GASt A large part of the burning or cutting at one of the larger southern refineries is done with oxygen and natural gas (60 pounds per square inoh pressure), A special torch with a l/l6" x 5/l6" tip made in the refinery shops is used. Two men with en average service of thirteen years spend a major portion of their working time on this natural gas. They wear goggles with JS shade Koviweld lens. Samples taken while burning holes in 3" standard pipe in the yard outside of welding shop with oxygen apd natu ral gas had a concentration of 471,811 particles, ten microns or less in size, per cubio foot. About 75# of these particles were slightly angular crystal line in appearance under the Konimeter microsoope, and were five microns or less in size; 25# were rough scale-like, opaque, ten microns or less in size. There were also many minute particles. - HEALTH HAZARDS PRODUCED BY WELDING AND BURNING OPERATI OKS; Although our study was confined to the fumes or dust produoed by Welding and Cutting opera tion the possibility of lead poisoning from welding or outting iron plates that have been previously coated with red lead should be pointed out. Lead poisoning from this source is rather common, especially in cutting up old scrap, bridges, tanks, and other iron structures that have through many years of use reoeived protective coatings of red lead. The action of the flame volatilizes this lead material and creates a smoke that is poisonous. The same hazard exists in cutting out rivets in new structures. It should also be pointed out that same of the welding rods contain manganese which is very poisonous when taken into the body. There is an ap parent hazard from volatilizing this material, or rather changing it to tho oxide of manganese, and breathing the fumes produoed. There are further dangers from carbon monoxide and oxygen deficiency owing to the use of gas-cutting or welding flames inside small tanks or similar confined spaces. It is becoming more and more recognized that persons engaged in cutting and welding operations, either by arc or flame, should have respiratory protec tion, in all work where there is a possibility of the workmen breathing fumes and dusts created. EM001528