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Hot Working of Metals 43, "Table of Chemical Hazards," for sum maries of their physical properties Dust is generated in many foundry proc esses and presents a two-fold problem clean ing to remove deposits and control at the point of ongin to prevent further accumulation Some foundries have found water under pressure or mixed with steam to be a good cleaning agent A combination water and compressed air hose with a special nozzle also does a good job With this method, how ever, workers should wear approved respi rators see Chapter 38, "Personal Protective Equipment " In any case, water cleaning should not be done during or immediately before melting and pouring These opera tions should be started only after all equip ment has been allowed to dry thoroughly Vacuum cleaning is probably the most satis factory method used for dust removal in found ries, and the special equipment needed is well worth the investment Once dust has been removed, further ac cumulation can be prevented by local ex haust systems which remove it at the point of ongin Installations which follow the rec ommendations of Chapter 29, "Local Exhaust Systems," will control dust effectively Solvents include many different substances, each of which must be evaluated on the basis of its chemical ingredients Proper labeling, limitations on quantities m use, and other methods of control as detailed m Chapter 41, "Industnal Hygiene," can help minimize the toxic and flammable hazards involved in solvent use Acrolein occurs in foundry operations as a result of the thermal decomposition of core oil Aluminum is not usually a toxic hazard in casting processes, but does present a fire and explosion hazard in dust-collecting systems Antimony is usually an unimportant con taminant in foundry operations Beryllium may produce a typical pulmo nary disease, such as reported in one plant casting a 1 per cent beryllium-copper alloy Carbon, as sea coal, is a common ingredient of molding sand used for facing Carbon dust may cause anthracosis, which produces characteristic lung shadows in an X ray, but is a relatively harmless condition Carbon monoxide is generated during some cycles m the operation of a cupola, page 811 Chromium is encountered in stainless steel casting as the element or the oxide Expo sures occur during melting, gate and head burning, and grinding Fluondes, sometimes m the form of cryo lite (sodium aluminum fluoride), are used in the manufacture of ductile iron and magnes ium castings Iron oxide fumes and dust are created dur ing melting, burning, pouring, grinding, weld ing, and machining of ferrous castings Exposure may be particularly high where manganese steel castings or oxygen-lancing of the furnace is involved Local exhaust can be used (Fig 28-1) Lead is the greatest health hazard m nonferrous foundries It forms the oxide in melt ing, pouring, and welding operations Ele mental lead dust is produced in cleaning and machining operations Magnesium dust or chips create senous fire and explosion hazards Physiological effects are confined to a form of "metal fume fever" from the inhalation of finely divided magne sium Manganese is usually associated with steel castings and bronze alloys in foundry work and presents no special control problem Phosphorus is used m the production of phosphor-copper Acute cases of poisoning have not been reported and chronic cases are rare The drying of phosphor-copper shot may produce phosphine gas Resins--phenol-formaldehyde and ureaformaldehyde-- are used in shell molding and create several hazards The pheno -for maldehyde type contain hexamethylenetetra mine ("hex") which is a skin irritant and highly explosive This type ofresin also decomposes on heating to give a mixture of phenol and formaldehyde vapors Urea decomposes to 802