Characterization of emission factors related to source activity for trichloroethylene degreasing and chrome plating processes.
Wadden-RA; Hawkins-JL; Scheff-PA; Franke-JE
Am Ind Hyg Assoc J 1991 Sep; 52(9):349-356
Four industrial processes were evaluated under production conditions to determine preliminary relationships between emissions and activities. The processes were a manually fed, open top trichloroethylene (79016) (TCE) degreaser; a conveyorized enclosed TCE degreaser; a chrome conversion coating line served by a microprocessor controlling the sequence of chemical solutions and immersion time of parts in perforated barrels; and a continuous decorative chrome electroplating line. Each process handled small parts such as automobile lock and key assemblies, ignition lock caps, and glove compartment knobs. To develop emission rates for the four processes, the pattern of simultaneously measured area concentrations at varying distances from the source was used. Four runs were available for activity analysis of the degreasing processes and five runs were available for the chromium plating conversion coating line. While all of the sources were served by functioning local exhaust systems, measurable amounts of TCE from the degreasers and chromium (7440473) (Cr) from the chrome plating lines were released into the surrounding workspaces. The variability in emission rate from each source could be reasonably related to at least one measure of source activity. Regression analysis of the emission rate and activity data gave emission factors of 16.9 grams (g) TCE per basket of parts for the open top degreaser, 1.0g TCE per 1000 parts for the enclosed degreaser, 1.48 to 1.64 milligrams (mg) Cr per 1000 parts processed in the hot CrO3/HNO3 tank for the chrome conversion coating, and 5.35 to 9.17mg Cr per rack of parts for chrome electroplating. The authors conclude that the activity based emission factors provide a more generalized method for expressing pollutant release from these types of sources. Used in conjunction with exhaust duct volumes and concentrations, the emission factors also allow control efficiency to be estimated on a mass basis. With more observations, the emission factors may also be used to predict area concentrations. For plating line areas similar to those studied, such concentrations will provide reasonable estimates of operator exposure as well.
NIOSH-Publication; NIOSH-Grant; Training; Chlorinated-hydrocarbons; Solvent-vapor-degreasing; Cleaning-compounds; Industrial-engineering; Control-technology; Analytical-methods; Exhaust-ventilation; Chromium-compounds
Occupational and Environ Med University of Illinois 2035 W Taylor Street Chicago, Ill 60612
American Industrial Hygiene Association Journal
University of Illinois at Chicago, Chicago, Illinois