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Emissions from the evaporative casting process.
Gressel MG; O'Brien DM; Tenaglia RD
Appl Ind Hyg 1988 Jan; 3(1):11-17
For purposes of identifying the contaminants produced, quantifying the major contaminants, and determining the temporal nature of the emissions, a study was made of the emissions from the evaporative casting process (EPC), a process utilizing a low density polystyrene foam facsimile of the part to be cast. The experimental arrangement made use of a sampling hood to contain the process emissions and deliver them to sampling points and aerosol sampling ports. Emission tests, conducted for the production of both aluminum and gray iron castings with an Eaton water pump housing as the test casting, were carried out with the EPC and, for comparison, the conventional green sand technology. Gas chromatographic mass spectrometric techniques and real time instrumentation were utilized to analyze the emissions. The average carbon-monoxide (630080), average aerosol mass, and average relative hydrocarbon concentrations as functions of time for the pouring, cooling and shakeout operations were calculated, and polynuclear aromatic hydrocarbon (PAH) concentrations were measured. Styrene (100425), benzene (71432), toluene (108883) and ethyl-benzene (100414) were identified as the major gaseous contaminants. The highest carbon- monoxide emission for both metals with the EPC process occurred during pouring. EPC molds produced more carbon soot and hydrocarbons during pouring than did green sand molds. Smoke levels during cooling were similar from both EPC and green sand. Screening analyses for 17 PAHs showed the presence of more species at generally higher concentrations with the EPC than with green sand. The authors conclude that soot generation in the EPC represents the most severe hazard for both aluminum and iron castings because of the associated release of PAHs.
NIOSH-Author; Workplace-studies; Metal-finishing; Metal-fumes; Metal-industry; Hot-metal-processes; Occupational-hazards; Polynuclear-aromatic-hydrocarbons
630-08-0; 100-42-5; 71-43-2; 108-88-3; 100-41-4
Issue of Publication
Applied Industrial Hygiene
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division