Record Display for the EPA National Library Catalog


Main Title Degreasing System Pollution Prevention Modification verses Industrial Hygiene Concerns.
Author Darvin, C. H. ; Wander., J. D. ;
CORP Author Air Force Engineering and Services Center, Tyndall AFB, FL.;Environmental Protection Agency, Research Triangle Park, NC. Air and Energy Engineering Research Lab.
Publisher 1990
Year Published 1990
Report Number EPA-68-02-4284; EPA/600/D-91/196;
Stock Number PB91-231142
Additional Subjects Air pollution control ; Chloroethanes ; Vapor degreasing ; Organic solvents ; Technology assessment ; Industrial hygiene ; Occupational exposure ; Stationary sources ; Indoor air pollution ; 1,1,1-Trichloroethane ; Wright Patterson Air Force Base
Library Call Number Additional Info Location Last
NTIS  PB91-231142 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 12p
The paper describes using a vapor degreaser at Wright-Patterson AFB to evaluate various modifications to reduce 1,1,1-trichloroethane (TCA) emissions. The modifications included freeboard extension, refrigeratedchiller, lip vent removal, covers, and combinations of each. The evaluation was aimed at maintaining a safe industrial hygiene environment. The lip vent, installed to maintain the breathing zone concentration of solvent at below the OSHA PEL (permissible exposure limit), also enhanced the discharge of solvent to the atmosphere. The solvent concentration of the discharge duct averaged 300 ppm solvent during normal operation. Freeboard extension reduced emissions by up to 50%, but at the expense of increased breathing zone concentration when the lip vent was off. Using extended freeboard combined with a below-zero freeboard chiller reduced the discharge of solvent by more than 75%, while keeping the breathing zone solvent concentration at 10 ppm and below, although the freeboard fan was turned off. Study results show that both industrial hygiene and air pollution concerns can be satisfied with proper engineering and operation of the degreasing system. The involved degreaser was a 26 sq ft (2.4 sq m), open-top vapor system. Approximately 93,000 lb (42,222 kg) of TCA solvent is used each year in the system. Premodification breathing zone solvent concentration averaged 10 ppm.