飛機除漆及噴漆作業中勞工之有機溶劑暴露評估

Exposure Assessment of Organic Solvents for Aircraft Paint Stripping and Paint Spraying Workers

本研究之目的為評估飛機除漆及噴漆作業勞工之有機溶劑暴露情形，探討造成暴露濃度差異之可能因素，以作為飛機維修棚廠設施規劃及推動安全衛生改善措施參考。評估之方法是針對國內三個飛機維修廠不同機型之飛機除漆及噴漆作業，依據勞委會及 NIOSH 公告方法進行定點及個人採樣分析。除漆作業之採樣是以直讀式儀器先進行偵測空氣中有機溶劑之濃度範圍，再以主動式採樣器作採樣分析；噴漆作業則以主動式採樣器分別對底漆及面漆之噴塗進行採樣分析。在飛機除漆作業之採樣分析結果顯示，地面上之作業勞工其二氯甲烷暴露濃度（42.01±31.86 ppm）遠高於距地面約四米高度的工作平台上之作業勞工暴露濃度（20.41±11.43 ppm） 。且二氯甲烷暴露濃度隨著工作時程之進展而有逐漸下降之趨勢（第一工作日之平均暴露濃度為 55.69 ppm，二十四小時後已下降為 14.82 ppm） 。在飛機噴漆作業之採樣分析結果顯示，噴塗底漆時，以甲苯（10.72±8.28 ppm）、二甲苯（5.03±2.87 ppm）、丙酮（18.85±24.46 ppm）之濃度較高；噴塗面漆時，則以甲苯（9.37±3.73 ppm） 、二甲苯（7.31±2.53 ppm）及甲戊酮（14.34±8.52 ppm）之濃度較高，惟所有噴漆作業勞工之有機溶劑暴露濃度均合於法規要求。綜合研究結論顯示，在各型飛機除漆之作業初期，作業環境中二氯甲烷之濃度高於我國法令規定之容許暴露濃度，需進行改善；而對於飛機噴漆作業，雖然氣態的有機溶劑之濃度不高，但粒狀污染物中的有機物則值得進一步進行探討。

The main objective of this study was to investigate the organic solvent exposure of aircraft paint stripping and paint spraying workers. The results of the personal exposure survey and environment measurement could be use as a reference for future chemical hazard control and workplace environment improvement for aircraft maintenance facilities. Three aircraft paint stripping/spraying workshops in Taiwan were selected, and the Council of Labor Affairs and NIOSH recommended sampling/analytical methods were used in this study. A direct reading instrument was utilized to preliminarily survey the exposure concentrations of methylene chloride in the depainting operation area. Then, activated charcoal tubes were used to investigate the personal and area exposure concentration of organic solvents in paint stripping and primer/topcoat spraying operations. During aircraft paint stripping, the experimental results reveal that methylene chloride personal exposure concentration (42.01±31.86 ppm) at the ground area was higher than that (20.41±11.43 ppm) at the working plateform 4 M high above the ground. The exposure concentration decreased from 55.69 ppm to 14.82 ppm (after 24hrs) for Airbus A300 paint stripping. During paint spraying, toluene (10.72±8.28 ppm), xylene (5.03±2.87 ppm), acetone (18.85±24.46 ppm) in primer spraying and toluene (9.37±3.73 ppm), xylene (7.31±2.53 ppm), methyl isobutyl ketone (14.34±8.52 ppm) in topcoat spraying were higher than other target compounds. All concentrations of organic vapor were below the Permissible Exposure Limit level (PEL) in primer and topcoat spraying operations. In summary, we have found that: (1) Exposure concentration of methylene chloride in the initial paint stripping operation stage of every aircraft model was over the PEL limit (50 ppm) set by the Council of Labor Affairs. Corrective actions are needed. (2) All solvents exposure concentrations were below the PEL limit during paint spraying operation, however, the organic compounds in particle pollutants deserve further investigation.