The development of controls and ink substitutes for reducing workplace concentrations of organic solvent vapors in a vinyl shower curtain printing plant.
Piltingsrud-HV; Zimmer-A; Rourke-A
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :52-53
During the summer of 1994 there were complaints of noxious odors reported by football players at a practice field located in Cincinnati. During Ohio Environmental Protection Agency (OEPA) investigations of industries surrounding the field, they inspected a printing facility located approximately one-quarter mile from the practice field. The facility produces vinyl shower curtains having screen-printed designs on them. Printing is carried out by means of movable screen printing units, having polyester screens approximately 6 x 6 feet. The printing units move over tables approximately 7 feet wide by 150 feet long. Four printing tables are localed side-by-side in a room approximately 50 x 200 x 12 feet high. The OEPA found that they were not the source of the odor in question; however, they were in regulatory noncompliance for uncontrolled volatile organic compound (VOC) discharges to the environs resulting from their use of organic solvents in their printing process. The company was then required to install an air incinerator at the facility to treat discharged air. The cost of such equipment was very high, and the capacity of the incincerator they installed resulted in a reduction in the flow of discharged air to approximately one-third of previous levels, increasing solvent vapor concentrations within the workplace atmosphere to levels exceeding NIOSH, OSHA, and ACGIH acceptable concentration levels for worker exposure. Consequently, workers were required to wear organic vapor cartridge respirators nearly full time. The printing company requested NIOSH assistance in finding methods to reduce solvent vapor exposures. NIOSH studies included the identification of the sources and relative magnitude of solvent emissions from the printing process, the design of controls for solvent emissions from the printing process, and the development of substitute inks using nonphotochemically reactive (as defined by the OEPA) solvents. Controls included the enclosure of the movable printer units to suppress evaporation of solvents from the printing screen. The NIOSH-developed ink used lower evaporation-rate solvents, having TLV values >100 ppm. Their nonphotochemically reactive status allowed OEPA removal of the requirement for the incineration of discharged air. This allowed substantial increases in dilution ventilation, enabling a reduction in worker exposures to less than one-third TLV additive levels, and a consequential removal of requirements for respirator usage. The solution was the result of a comprehensive review of all facets of the problem, including OEPA regulations. It also required teamwork with the company, The Ohio Bureau of Workers Compensation, and the OEPA.
Solvent-vapors; Printing-industry; Printing-inks; Incineration; Incinerators; Engineering-controls; Environmental-pollution; Control-equipment; Control-technology; Workplace-studies; Vinyl-esters; Volatiles; Organic-solvents; Organic-compounds; Air-contamination; Breathing-atmospheres; Employee-exposure; Exposure-levels; Exposure-limits; Emission-sources; Photochemical-reactions; Ventilation
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia