去漬油中烷類碳氫化合物暴露危害評估

Hazardous exposure assessment of alkanes hydrocarbon compound in cleaning naphtha

李焉華(Yan-Hua Li)

指導教授 ： 劉宏信

中山醫學大學/健康管理學院/職業安全衛生學系/碩士(2022年)

https://doi.org/10.6834/csmu202200068

摘要

去漬油是一種原油精煉烴類液體的中間產物，在工業中經常被用作清洗液、油漆稀釋劑、橡膠添加劑等，在一般日常生活中也常被當作去汙劑使用。然而，由於生產成本的考量，去漬油的成分並非是單一的純化合物，而是各種碳氫化合物組成的混合物，在去漬油常見的成分中，包含了正己烷、正己烷異構物、正庚烷、正庚烷異構物、甲基環戊烷、甲基環己烷。然而除了正己烷外，其他未列管之烷類碳氫化合物不需定期依勞工作業環境監測實施辦法實施監測，往往會忽略這些有容許濃度標準以外的其他物質對勞工的危害風險。因此，本研究目的為探討使用去漬油的行業中，勞工暴露於正己烷、正庚烷及其同分異構物等物質之濃度情形，並透過相加效應計算，評估勞工實際之暴露情況。
　　本研究共選擇了6間使用去漬油進行模具擦拭、零件清洗等製程的工廠，藉由區域及個人採樣方式探討勞工於作業場所暴露烷類碳氫化合物之情況，樣本是參考CLA 1228分析方法，以氣相層析火焰離子化偵檢(GC-FID)分析各項物質濃度，並評估相加效應結果。
　　研究結果顯示，使用擦拭清潔工件之工廠暴露量均較低，且沒有超過容許濃度；使用浸泡清洗則有高濃度的暴露，如E廠8-1點在短時間採樣中，3-甲基戊烷(1778.757 ppm)超過了2倍容許濃度，正己烷濃度(121.451 ppm)也有超標的情形。B廠則是去漬油儲存罐開蓋瞬間，會有高濃度物質溢散導致正己烷等物質濃度超標(76.661 ppm)。部分樣本濃度超過了二分之一八小時日時量平均容許暴露濃度，相加效應計算後發現總和有大於1之情形，顯示實務上已超過法令之規定，且對勞工健康已有危害之風險。
　　本研究顯示一般工廠實施作業環境監測時，作業環境監測機構及廠商只測量作業環境監測辦法所定之採樣物質，對職業安全衛生法第十二條第一項的規定都未執行。若對有容許濃度物質都採定量推估模式，可能低估勞工暴露風險。對於類似去漬油這類有複雜成分的化學品暴露評估時，建議政府是否應思考當實施正己烷定期作業環境監測時，也應同時將有相加效應可能，且有容許濃度之物質一起納入暴露評估，以真正評估勞工暴露危害風險。

關鍵字

去漬油 ； 烷類碳氫化合物 ； 同分異構物 ； 相加效應

並列摘要

Cleaning naphtha is an hydrocarbon liquid of intermediate product by refining crude oil. It is often used as cleaning fluid, paint thinner, rubber additive, etc. in the industry. It is also often used as a eradicators in daily life. However, due to take cost of production into account, the composition of cleaning naphtha is not a pure compound, but a mixture of various hydrocarbons. Among the common components of cleaning naphtha, it contains n-hexane, n-hexane isomers, n-heptane, n-heptane isomers, methylcyclopentane, methylcyclohexane. However, in addition to n-hexane, other unregulated alkane hydrocarbon do not need to be regularly monitored in accordance, the risk of hazards to workers from these other substances with permissible exposure limit standards is often overlooked. Therefore, the purpose of this study is to investigate the concentration of workers exposed to n-hexane, n-heptane and its isomers in industries that use cleaning naphtha, and to evaluate the actual exposure of workers through additive effect calculation.
　　A total of 6 factories that use cleaning naphtha for mold wiping, parts cleaning and other processes were selected for this study. Investigate the exposure of workers to alkane hydrocarbons in the workplace by means of regional and individual environmental monitoring and sampling The samples were based on the analysis method of CLA 1228, analyze the concentration of each substance by gas chromatography flame ionization detection (GC-FID), and evaluate the additive effect.
　　The results of the study showed that all factories using wipes to clean workpieces had lower exposures and did not exceed tolerable concentrations. Immersion cleaning is used to expose high concentrations. For example, in the short-time sampling at No. 8-1 of Plant E, 3-methylpentane (1778.757 ppm) exceeded 2 times the allowable concentration, and the n-hexane concentration (121.451 ppm) also exceeded the standard situation. Factory B is the moment when the oil storage tank is opened, high concentrations of substances will overflow, causing the concentration of n-hexane(76.661 ppm) and other substances to exceed the standard. The concentration of some samples exceeded 1/2 permissible exposure limit-time weighted average(PEL-TWA). After the calculation of the additive effect, it was found that the total was greater than 1, indicating that the actual situation exceeded the legal requirements, and there was a risk of harm to labor health.
　　The concentration of some samples exceeds the allowable exposure concentration for one-half of eight hours. After the calculation of the additive effect, it is found that the sum is greater than 1. It is regarded as a sample exceeding the allowable concentration, indicating that in addition to investigating whether each substance exceeds the exposure limit, it should be added Evaluate the additive effect between substances, and consider the complex composition of stain removal oil, include substances other than n-hexane in regular environmental monitoring, provide workers with appropriate protection measures and strengthen the capture efficiency of ventilation equipment to reduce the risk of labor health hazards .
　　This study shows that when working environment monitoring is implemented in general factories, working environment monitoring agencies and manufacturers only measure the sampling substances specified in the working environment monitoring method, and do not implement the provisions of Article 12, Paragraph 1 of the Occupational Safety and Health Act. If the quantitative estimation model is used for all substances with permissible exposure limit, the risk of labor exposure may be underestimated. When assessing exposure to chemicals with complex components such as cleaning naphtha, it is suggested that the government should consider whether it should also include substances with possible additive effects and allowable concentrations when implementing regular operating environmental monitoring of n-hexane. Exposure assessment to truly assess the risk of labor exposure hazards.

並列關鍵字

Cleaning naphtha ； Alkane hydrocarbons ； Isomers ； Additive effect

參考文獻

[1]羅錦泉, 職業性烷屬烴化合物、硝基及胺基衍生物中毒認定參考指引, 勞動部職業安全衛生署, 105 年 11 月,頁3-6。

[2]Y. Ono, Y. Takeuchi, N. Hisanaga, A comparative study on the toxicity of n-Hexane and its isomers on the peripheral nerve. International Archives of Occupational and Environmental Health (1981), 48:289-294.

[3]Takeuchi Y. A comparative study on the neurotoxicity of n-pentane, n-hexane, and n-heptane in the rat, British Journal of Industrial Medicine 1980;37:241-247,1980, 1980.

[4]H.Y. Kim, M.G. Kang, T.G. Kim, C.W. Kang, toxicity of methylcyclohexane and its effect on the reproductive system in SD rats. Safety and Health at Work (2011), 2(3):290-300.

[5]M. Neghab, Electrophysiological studies of shoemakers exposed to sub TLV levels of n-hexane. Journal of Occupational Health (2012), 54: 376–382.