評估金屬加工液之添加劑在不同防護情況下的皮膚滲透特性

Abstract

近年來，金屬相關產業之員工人數與工廠數都有增加的趨勢，而工廠內主要的工作內容為金屬產品的加工；在加工製程中常需使用金屬加工液，其主要功能為潤滑與冷卻機具及金屬加工元件，並可一併帶走製程中產生的細屑。由於金屬加工液的成份複雜，因此其暴露可能造成的不良健康效應非常值得關注(包括：吸入及皮膚接觸危害等)。以接觸性皮膚炎為例，其為常見的職業性疾病；文獻即指出暴露於金屬加工液容易造成接觸性皮膚炎，而如何能有效預防相關危害的發生，顯然是金屬加工相關產業不容忽視的職場健康議題。 本研究主要針對國內之金屬加工產業進行職業衛生相關討論，包括透過問卷了解國內金屬加工廠勞工的工作型態、防護用具配戴狀況及皮膚不適之相關病史等，並使用經皮吸收擴散槽來模擬金屬加工廠勞工之常見皮膚暴露情形(例如：使用手套、隔離霜與否，以及同時使用兩種防護用具等)，以討論在不同接觸狀況下皮膚對於各種物質組成之吸收情形。 本研究共完成了13間金屬加工產業的現場訪視，另外亦透過經皮吸收擴散槽之模擬評估勞工常見之暴露狀況，同時探討手套、隔離霜與其他相關產品之防護效果(例如：皮膚乳霜、皮膚炎藥膏等)；在經皮吸收擴散槽的模擬實驗中，共模擬了10種情境，並討論11種不同金屬加工液添加劑的皮膚滲透情形。研究結果顯示，若未使用個人防護具，測試之添加劑物質於很短時間內即會滲透進入皮膚，而若使用適當的防護措施，能使滲透時間延滯至接觸後的1.5至2小時不等，例如：使用丁腈手套（Nitrile gloves）最高能延滯至接觸後的3小時；皮膚乳霜甚至能夠延滯至接觸後的6小時。除此之外，使用皮膚防護用具亦能降低其滲透量(依添加劑物質之不同，約可降低56-100%的滲透量)。 根據本研究之結果，建議使用適當的個人防護措施，若能使用手套者，橡膠手套具有最佳的防護效果，若操作機具時不適合使用手套，則可選擇塗抹皮膚乳霜、皮膚炎藥膏或較低含水量的隔離霜，上述之皮膚防護用具皆可降低對金屬加工液中添加劑的接觸情形，以減少有害物質的皮膚暴露，進而保障員工的健康。

The metalworking factories mainly produce a variety of metal products which have been widely used in different industries. The main task in a metalworking factory is to process the metal products, which involves the use of metalworking fluids (MWFs) to lubricate and cool the tools and metal pieces. However, due to its complex ingredients, there are many potential health hazards which might occur during the use of MWFs. For example, it has been reported from various literature that exposure to MWFs was highly associated with the occurrence of contact dermatitis. In order to protect people from developing occupational skin diseases in the MWFs operating environment, this study determined the permeation parameters of skin absorption for the contact of MWFs under different dermal protective measure to evaluate their protective efficiency. This study focused on chemicals which are common used for additives in MWFs (especially biocide, anti-corrosion inhibitor and anti-oxidation inhibitor) that might more likely cause skin abnormality and contact dermatitis. Parameters, including chemical compositions and contact conditions (e.g., whether gloves and barrier cream were in use or not), were examined to elucidate their effects on skin absorption. In addition, the Hanson vertical diffusion cell (VDC) was performed to simulate the common situation of workers’ skin exposures. From the walk-through survey in 13 metalworking factories, the symptoms of skin abnormality in metalworkers were observed. Nearly all the metalworkers used gloves for protection and none of them had the experience of using barrier cream. Nevertheless, the use of wrong types of gloves was also observed (e.g., cotton, where chemicals might be permeated easily). On the other hand, the SPME procedure coupled with GC/MS analysis for the determination of chemicals in the PBS solution was established in this study. We found that chemicals can permeate through skin via dermal exposure. The permeability, including flux and lag time, for chemicals through skin were different with various protective measures. The results suggested that permeation occurred shortly after the exposure when the MWFs contacted skin directly. Besides, the permeation will be delayed for 1.5~2 hours when there was effective skin protection employed. For example, the use of rubber gloves, and nitrile glove, which is recommended by NIOSH, were found to lower the amounts permeated significantly as well as to extend the lag time for permeation. However, for mechanical safety reason, glove wearing might not be allowed for certain operations. Under those circumstances, it was observed that applying skin cream, dermatitis ointment could also protect the skin from possible exposure with the amount permeated lowered to 28~100%. In conclusion, personal skin protection is highly suggested for the workers who are associated with the operations using MWFs. The most recommended protective measure was rubber gloves, but if there are not appropriate to use gloves, skin cream was also recommended for metalworkers.