微粒防護衣之測試方法探討

Search for test methods of particle protective clothing

林郁婷(Yu-Ting Lin)

指導教授 ： 陳志傑

國立臺灣大學/公共衛生學院/職業醫學與工業衛生研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.00018

摘要

個人防護具是用來保護工作人員避免有害物經由皮膚暴露，截至目前為止，雖然有許多的方法可用來測試防護衣之性能，但這些方法均著重於對液體噴濺或蒸氣危害之防護性能的測試，而對於空氣中粒狀物防護性能的測試方法並不完整。其次，目前的防護衣由於著重在防液體滲透的功能，因此降低了防護衣的透氣性，以致於使用者穿著時可能會造成熱、物理與心理上的壓迫，或者是影響到活動視野、行動與溝通障礙等的現象。站在防護衣正確使用的觀點上，過度和不足的保護都必須加以避免。因此，本研究的最終目的在於訂定微粒防護衣之測試方法。
在此研究中，使用市售之防護衣進行微粒穿透率及空氣阻抗測試。過濾風速範圍設定於0.1至10 cm/sec，以了解過濾機制中重力沉降與慣性衝擊之轉換過程，另外使用氣動微粒分徑器(Aerodynamic Particle Sizer, APS)量測上游及下游微粒濃度及粒徑分佈。首先進行市售防護衣微粒過濾特性，其後使用有彈性的聚氨酯海綿作為測試濾材，此材質的優點是結構均勻且低充填密度產生低壓降，而且不論如何擠壓、改變其充填密度都不會影響到纖維直徑，更重要的是經過清洗之後可重複使用，再現性良好。
微粒穿透率數據結果顯示C級化學防護衣的防護特性最好，卻有高空氣阻抗，過度保護可能會有不舒適的情況發生，而其他防護衣在表面風速為1 cm/sec以上都有較高的微力穿透率。建議醫療人員在感染病房內進行醫療行為時減慢動作速度，以降低微粒穿透過防護衣的機會。為了發展較佳過濾品質的微粒防護衣，建議未來微粒防護衣測試方法為：(1) 粒數中數粒徑為10 μm之固態或液態微粒作為測試微粒；(2) 過濾風速為5 cm/sec；(3) 利用計算微粒飛行時間的儀器（如：APS）量測1~20 μm之數目濃度及粒徑分佈。

關鍵字

微粒防護衣 ； 超低風速

並列摘要

Personal protective clothing is designed to protect workers against hazardous substances that might come into contact with the skin. Several widely accepted test methods are available to measure barrier properties of protective clothing against liquid and vapor assaults. However, there is no officially accepted test method for particulate protective clothing, probably due to lack of aerosol penetration data. For any given situation, equipment and clothing should be selected that provide an adequate and appropriate level of protection. Overprotection as well as underprotection can become hazardous and should be avoided. Accordingly, the ultimate goal of this study is to establish the test method for particle protective clothing.
In the present study, a variety of protective garments, currently used in health care industry, were tested for aerosol penetration and air resistance. Filtration velocity ranging from 0.1 to 10 cm/sec was employed to study the flow dependency. An Aerodynamic Particle Sizer was used to measure the aerosol concentrations and size distributions upstream and downstream of the garment media. Besides the protective garments, the flexible polyurethane foam was selected as a reference filter medium for their relatively low pressure drop due to the open pore skeletal structure and low packing density. The pressure drop across the filter medium was monitored by using an inclined manometer.
Aerosol penetration data showed that C-class garment performed well but at the cost of high air resistance. The overprotection may lead to uncomfortable physical conditions. Other garments showed unacceptable high aerosol penetration when the face velocity is above 1 cm/sec. An advisory should be issued to health care workers not to make large and fast move in the infection-control area, to avoid unnecessary high aerosol penetration. Particulate protective clothing of better filtration quality apparently needs to be developed. We propose the following items to be included in the future test method of particulate protective clothing: (1) aerosols (solid or liquid) with count median diameter of 10 μm to be the test agent, (2) face velocity of 5 cm/sec, and (3) a high resolution time-of-flight machine (such as Aerodynamic Particle Sizer) covering aerosol size from 1 to 20 μm to be used for measuring aerosol concentration and size distribution.

並列關鍵字

particle protective clothing ； extra-low face velocity

參考文獻

British Standard, BS EN 466-1, 1995; Protective clothing- Protection against liquid chemicals.

Brown, R.C., 1984; A Many-fiber Model for Airflow through a Fibrous Filter. J. Aerosol Sci. Vol. 15, no. 5, 583-593.

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