機械加工廠水性金屬加工液之油霧滴危害暴露調查

An Investigation of Hazard Exposure for Mists from Water-based Metalworking Fluids in Machinery Processing Factories

本研究調查機械加工廠使用水性金屬加工液產生油霧滴之職業暴露，以作為該製程危害控制及預防之參考。研究對象為4家不同規模機械加工廠，針對其使用水性金屬加工液之作業流程分析其危害特性及監測油霧滴作業環境，以美國NIOSH 5524方法進行分析。
在環境監測結果發現，對4家機械加工廠共現場採集42個樣品進行分析，勞工個人總氣膠之日時量平均濃度介於0.024至0.387 mg/m3，總平均為0.168±0.111 mg/m3。勞工個人油霧滴之日時量平均濃度介於0.012至0.290 mg/m3，總平均為0.084±0.081 mg/m3。在區域監測方面，總氣膠之日時量平均濃度介於0.027至0.532 mg/m3，總平均為0.139±0.116 mg/m3，油霧滴之日時量平均濃度介於0.012至0.429 mg/m3，總平均為0.065±0.095 mg/m3。在個人暴露濃度比較上，磨床機台操作者之平均暴露濃度不論在總氣膠及油霧滴濃度皆高於大型機台操作者，而銑床機台操作者之平均暴露濃度在總氣膠亦高於大型機台操作者。物件更換較為頻繁者（<60min）其勞工油霧滴平均暴露濃度顯著高於更換較不頻繁者（>60min）。在定點濃度比較上，開放式機台在油霧滴平均濃度顯著高於非開放式機台。不過，上述結果均未超過我國油霧滴容許暴露標準（5 mg/m3），但仍建議事業單位參採各項危害防制策略，降低勞工之危害暴露。

This study was aimed at investigating the hazard exposure to mists caused by the use of water-based metalworking fluid in machining factories as a reference for the control and prevention of hazards in the process. The study objects were four machining factories of different scales. The hazard characteristics of the process and the workplace monitoring of mists from water-based metalworking fluids were analyzed. The US NIOSH 5524 method was used in this workplace monitoring.
The workplace monitoring on workers’exposure to oil mists was performed on four such factories, with a total of 42 samples measured. The measurement results indicated that worker personal time-weighted average exposures to total aerosol ranged from 0.024 to 0.387 mg/m3, with an overall mean of 0.168±0.111 mg/m3, while worker personal time-weighted average exposures to metalworking fluid aerosol ranged from 0.012 to 0.290 mg/m3, with an overall mean of 0.084±0.081 mg/m3. Conversely, a level of 0.027 to 0.532 mg/m3 (overall mean of 0.139±0.116 mg/m3) was found for total aerosol, and 0.012 to 0.429 mg/m3 (overall mean of 0.065±0.095 mg/m3) for metalworking fluid aerosol from area monitoring. In terms of the comparison of worker personal time-weighted average exposures, the overall mean of grinding machine operators was higher than that of large machine operators in both total aerosol and metalworking fluid aerosol, and that of milling machine operators was also higher than that of operators of large machines in total aerosol. The overall mean for metalworking fluid aerosol in those who changed objects more frequently (<60min) was significantly higher than those who changed less frequently (>60min). Additionally, for the comparison of area monitoring, the overall mean for metalworking fluid aerosol in the open-type machinery was significantly higher than one in the enclosure-type. However, none of the above results exceeded the current Taiwan permissible exposure limit for oil mists (5 mg/m3), but it is still recommended that business entities use various hazard prevention strategies to reduce the hazard exposures of workers.