This study was conducted at seven degreasing processes in plating plants located in Seoul, Incheon, Ansan, and Taejeon areas from July 21 to august 27, 1992. This study was performed to assess the TWA exposures to trichloroethylene (TCE) and evaluate factors affecting TCE concentrations in degreasing process. Two-Point Eddy Diffusional Model suggested by Wadden et al. was employed to calculate emission factors according to degreaser type.
Results are summarized as follows.
1. The TWA exposures of the degreasing operators ranged from 1.4 ppm to 123 ppm, and those of three plants out of seven were exceeding 50 ppm of both the Korean and U.S. OSHA standards. Degreasing assistant of Plant B, was exposed to 59 ppm.
2. The average concentrations at the distance 0, 1.5, 3.0 m from the degreasers were 1,014, 24, and 18 ppm, respectively, and showed a significant difference by distance (p$lt;0.01).
3. The emission of TCE was reduced by installing local exhaust systems, condensers, and refrigeration lines at the degreasers (p$lt;0.01).
4. The major factors related to exposure of operators were workload (r=.9621, p$lt;0.01) and dimensions of degreasing room (r=-.8667, p$lt;0.05).
5. If the air in degreasing room is mixed violently by other factors in addition to diffusion, the emission factors can not he evaluated because the important hypothesis of the Two-Point Eddy Diffusional Model can not be accepted.
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