过滤罐微生物气溶胶过滤效率及其评价方法的研究

目的 建立防护面具高效过滤罐微生物气溶胶测试评价方法,对过滤罐的实际防护效果进行测试评价.方法 Serratia marcescens作为模式细菌繁殖体气溶胶、Bacillus subtilis var niger芽孢作为模式芽孢气溶胶、噬菌体f2作为模式病毒气溶胶,使用实验室建立的微生物气溶胶检测技术平台,人工发生模式微生物气溶胶,分别在过滤罐过滤前后使用空气微生物采样器进行定量采样,根据过滤前后模式微生物气溶胶的浓度分别计算细菌、芽孢、病毒气溶胶过滤效率.1-1、1-2、1-3、1-44个只含有高效过滤材料的过滤罐分别测试了Serratia marcescens、Bacillus subtilis var niger、噬菌体f2气溶胶的过滤效率.543、544 2个装有活性炭的高效过滤罐测试了对Scrratia marcescens气溶胶的过滤效率.结果 1-1、1-2、1-3 3个高效过滤罐对Serratia marcescens、Bacillus subtilis var niger芽孢、噬菌体f2的气溶胶的过滤效率为100.000%,1-4高效过滤罐对Bacillus subtilis var niger芽孢气溶胶的过滤效率为990997%、Serratia marcescerts和噬菌体f2气溶胶的过滤效率均为100.000%.加入活性炭后543、544 2个过滤罐对Serratia marcescens气溶胶的过滤效率均为100.000%.结论 建立的检测方法可以用于高效过滤罐微生物气溶胶防护效果的评价,高效过滤罐(包括装有活性炭者)微生物气溶胶防护效果均佳.     

一种达到面具防护水平的生物防护口罩

用0．075μm的NaCl气溶胶和金黄色葡萄球菌及大肠杆菌F2噬菌体气溶胶，对FS9901型平面-腔式可变的一次性生物防护口罩进行了滤材过滤效率、通气阻力和负载能力的评价；用口罩脸形密合度测试仪在8种规定的动作下进行了实际佩戴效果的测试。结果表明，口罩对3种气溶胶的过滤效率达到99％以上，通气阻力〈250Pa，口罩负载达到150mg时的通气阻力仍低于其正常使用标准．大部分受试者用一次性防护口罩检测模式检测，实际佩戴时的脸形密合度超过了国际通用检测仪器的极限．用防护面具检测模式检测的脸形密舍度平均值为134．5，是目前国际上防护性能最高的一次性防护口罩，基本达到了半脸式面具的防护水平。本口罩储存时为平面结构，使用为腔式结构，体积小，重量轻，便于部队装备和使用。     

医用面罩材料空气微生物过滤效率标准测试方法与装置的研究

目的 建立医用面罩、口罩等感染防护材料空气微生物过滤性能的标准测试方法 和装置.方法 在受检样品上游发生微生物气溶胶,采用在受检样品上下游同时采样的方法 控制检测精度,用增加支路的方法 实现变流量检测.结果 该测试方法 和装置检测精度可达99.96%,可变流量检测范围为0～85 L/min,测试装置结构紧凑、性能稳定、易于操作.结论 标准测试方法 和装置能够广泛应用于感染防护相关材料微生物气溶胶过滤效率的检测和评价.     

正压送风过滤式医用防护装备的微环境研究

目的 研究正压送风过滤式防护装备的过滤效率和送风量对其微环境的影响.方法采用模拟病毒（大肠杆菌噬菌体f2）雾化生物气溶胶进行高效空气过滤器过滤效率的测定;在夏季进行4 km/h行走速度的模拟作业,考察不同送风量对装备微环境内的氧、二氧化碳含量和温度、湿度的影响;在3家定点医院进行临床试用.结果 高效空气过滤器可滤除空气中99.99%模拟病毒.送风量在75～125 L/min范围时,防护装备微环境内氧含量为19.6%～20.1%（健康人生理安全限值要求不低于14.6%）、二氧化碳含量为0.43%～0.57%（健康人生理安全限值要求不高于1.0%）;温度为32.0℃～32.2℃、湿度为49.7%～59.4%（健康人生理安全限值是温度31℃、湿度85%或温度38℃、湿度50%）.各项指标均能够满足健康人正常工作负荷时的生理要求.经试用,临床医护人员感觉整体防护性良好,不憋气,视窗不起雾,无医护人员感染.结论 该医用防护装备的微环境能满足健康人正常工作负荷的生理需求.     

医用口罩防护效果研讨

目的 探讨各类医用口罩的防护效果,确定使用范围,合理选用.方法 对各类医用口罩执行的技术标准进行分析,指导医务人员合理选用.结果 医用防护口罩有国家技术标准,颗粒过滤效率≥95％,决定其能阻挡经空气传播的直径＜5 μm的感染因子或近距离接触经飞沫传播的感染因子;医用外科口罩有行业技术标准,对气溶胶的过滤效率＞30％,细菌过滤效率＞95％;当体液以16.0 kPa(120 mm Hg)压力喷向口罩外侧面后,口罩内侧面无渗透;普通医用口罩仅对0.3 μ m直径的气溶胶达到20.0％～25.0％的防护效果.结论 医用防护口罩能阻止经空气或飞沫传播的大部分细菌、病毒等病原体,适用于呼吸科传染病区、发热门诊等科室;医用外科口罩可以阻隔大部分细菌和部分病毒,能阻隔血液、体液、分泌物等的喷溅,既能防止医务人员被感染,又能防止医务人员向外界传播病原菌,适用于临床医务人员的基本防护.     

正压式通气防护口罩的防护效能、适配性及复用可能性评测

目的：测定自主研发的正压式通气防护口罩的防护效能、适配性和复用可能性。方法：依据GB 30864—2014《呼吸防护动力送风过滤式呼吸器》和GB 50346—2011《生物安全实验室建筑技术规范》，利用微压计和质量流量计测试该正压式通气防护口罩的送风量，采用气溶胶发生器和粒子计数器检测其过滤效率和泄漏率；选取60名健康受试者，通过问卷调查受试者佩戴口罩的主观感受。通过汽化过氧化氢熏蒸消毒该口罩，探索其复用可能性。结果：该款正压式通气防护口罩在不同送风量下对粒径为0.3～0.5μm的气溶胶粒子的过滤效率均达到99.98%以上，泄漏率均低于0.02%。调查结果表明，该口罩具有更好的通气程度、对血氧饱和度的影响更小、在活动状态下佩戴者产生的不适感更轻。该口罩经汽化过氧化氢消毒后，生物指示剂72 h培养结果为阴性，能够达到复用要求。结论：自主研发的正压式通气防护口罩防护效能优良，在通气程度方面表现突出，并且具有复用可能性。     

某种正压生物防护服的病毒气溶胶防护性能评价

目的 评价某种正压生物防护服对病毒气溶胶的防护效果.方法 制备Phi-X174噬菌体悬液,在气溶胶密闭舱室内发生Phi-X174噬菌体气溶胶,应用空气动力学粒子分析仪检测粒子直径,在高送风档和低送风档条件下,调节气溶胶密闭舱室内的湿度,用安德森六级采样器采样,通过计数噬菌体噬斑数评价该正压生物防护服对病毒气溶胶的防护效率.结果 Phi-X174噬菌体气溶胶粒子质量中值直径约为0.922 μm,气溶胶粒子本底浓度＞2.0×104个/m3,在不同的测试条件下,该正压生物防护服内病毒气溶胶浓度为0 ～21PFU/m3,对Phi-X174噬菌体气溶胶粒子防护效率均＞99.9％,送风量(P=0.84)、环境湿度(P=0.33)以及采样时间(P=0.07)对正压防护服防护效率的影响无统计学意义.结论 该正压生物防护服对Phi-X174噬菌体气溶胶的防护效果较好.     

防护口罩防护性能影响因素研究进展

防护口罩是以过滤空气中的颗粒物、保护人体健康为目的的呼吸防护用品，其防护性能主要取决于口罩 的过滤效率和佩戴者适合性检验结果。不同的过滤材料可造成过滤效率的巨大差异，过滤材料本身的纤维介质厚度、空隙率和纤维直径会影响过滤效率；口罩层数增加在提高过滤效率的同时也会增加呼吸阻力。适合性检验结果的影响因素很多，大部分源于口罩自身设计，如口罩形状、尺寸、口罩带张力及鼻梁条类型等，佩戴者自身脸型及佩戴规范程度也是影响因素之一。     

防护口罩的过滤性及舒适性评价

目的：对国内市场上常见的防护口罩的过滤性及舒适性进行评价，为防护口罩改进提升提供依据。方法：采取线上销售平台和线下调研的抽样方法，选取国内市场上常见的77款防护口罩，参照GB 19083—2010《医用防护口罩技术要求》和GB 2626—2019《呼吸防护自吸过滤式防颗粒物呼吸器》对其过滤效率、呼吸阻力和死腔进行检测。采用SPSS 22.0软件进行统计分析。结果：防护口罩的过滤效率符合国家标准的不足75%，颗粒物防护口罩滤材的过滤效率较医用防护口罩更稳定；舒适性指标的合格率高于过滤效率，其中死腔全部合格且测试结果远低于标准要求；不同类型口罩在舒适性指标测评结果上不存在差异（P>0.05），口罩的折叠方式会影响舒适性指标测评结果（P<0.05）。结论：目前国内防护口罩的过滤性及舒适性有待进一步提高，高效低阻滤材的防护口罩是今后的研发重点。     

一种新型高效生物防护口罩的防护性能测试

目的对FS9901型生物防护口罩的防护效果进行测试评价。方法采用国家标准测试方法对该口罩的滤材过滤效率、通气阻力、负载能力、口罩脸形密合度进行测试。结果该口罩的过滤效率达到99%以上;通气阻力<250 Pa,低于正常使用标准;脸形密合度>200,超过了国际通用检测仪器的极限。结论该口罩是目前国内外防护用品市场上已有的防护性能最好的一次性生物防护口罩。此外,该口罩在使用时自动变为腔式结构,而在储存时为平面结构,体积小,重量轻,非常易于储运和使用。     

一种多功能空气微生物采样箱的研制

目的：研制一种用于集固体介质采样、液体介质采样于一体的便携式空气微生物采样装置。方法：根据气溶胶粒子的惯性撞击原理设计改进二级Andersen筛孔式固体撞击采样器;运用气流的冲击清洗和喷雾原理,设计体积更小的AGI-10液体冲击式采样器;利用负压过滤采样原理,设计新型的水过滤采样器的机械结构;根据样本采集的要求,采用计算机、传感器、自动控制等高新技术,设计一机多用的采样动力系统;精心规划,将多种仪器设备及现场采样必需的辅助器材集成于一体,形成便携式采样装备。结果：实验证明,改进型二级Andersen采样器比原有二级采样器采样效率提高30%以上,改进型AGI-10液体采样器与原AGI-10采样器采样效率相当,水过滤采样器能够有效浓缩采集到的液体中微量的细菌。多功能空气微生物采样动力系统也实现了采样过程的一键式操作,采样流量稳定、准确。结论：多功能空气微生物采样箱实现了环境现场采样装备的快速、便携,且不受现场环境地形和供电条件的约束,满足环境空气微生物样本采集的需求。     

Electrostatic N-95 respirator filter media efficiency degradation resulting from intermittent sodium chloride aerosol exposure

The effects of intermittently loading small masses of sodium chloride aerosol on the filtration efficiency of N-95 filtering facepiece respirators was investigated. The National Institute for Occupational Safety and Health (NIOSH) certifies that N-95 respirators must provide at least 95 percent filtration efficiency against a sodium chloride aerosol challenge as per the respirator certification (42 CFR 84) test criteria. N-95 respirators are specified for protection against solid and water-based particulates (i.e., non-oil aerosols). New N-95 respirators from three different manufacturers were loaded with 5 +/- 1 mg of sodium chloride aerosol one day a week, over a period of weeks. Aerosol loading and penetration measurements were performed using the TSI 8130 Filter Tester. Respirators were stored uncovered on an office desktop outside the laboratory. To investigate environmental and temporal effects of filters being stored without sodium chloride exposure, control respirators were stored on the desk for various lengths of time before being initiated into weekly testing. For all manufacturers' respirators, the controls showed similar initial penetrations on their day of initiation (day zero) to those of the study samples on day zero. As the controls were tested weekly, they showed similar degradation rates to those of the study samples. Results show that some of the manufacturers' models had penetrations of greater than 5 percent when intermittently exposed to sodium chloride aerosol. It is concluded that intermittent, low-level sodium chloride aerosol loading of N-95 respirators has a degrading effect on filter efficiency. This reduction in filter efficiency was not accompanied by a significant increase in breathing resistance that would signal the user that the filter needs to be replaced. Furthermore, it was noted that the effect of room storage time prior to initial exposure was much less significant.     

"Worst case" aerosol testing parameters: I. Sodium chloride and dioctyl phthalate aerosol filter efficiency as a function of particle size and flow rate

The efficiency of filter media is dependent on the characteristics of the challenge aerosol and the filter's construction. Challenge aerosol parameters, such as particle size, density, shape, electrical charge, and flow rate, are influential in determining the filter's efficiency. In this regard, a so-called "worst case" set of conditions has been proposed for testing respirator filter efficiency in order to ensure wearer protection. Data collected on various types of filters (dust and mist; dust, fume, and mist; paint, lacquer, and enamel mist; and high efficiency) challenged with a worst case-type sodium chloride (NaCl) and dioctyl phthalate (DOP) aerosol are presented. The particle size of maximum penetration varies as a function of filter type and was less than 0.25-micron count mean diameter (CMD) in all cases. The count efficiency for high efficiency filters was greater than 99.97% at worst case testing conditions, but the worst case count efficiencies for dust and mist; dust, fume and mist; and paint, lacquer and enamel mist filters were not nearly as efficient as existing test methods indicate. Also, as the test flow rate is increased, the count efficiency decreases. Thus, respirator filters were found to conform to the prediction of single-fiber filtration theory.     

负压救护车排风净化装置的研制与应用

目的研制一种负压救护车排风净化装置,使安装该装置的普通救护车通过电路连接、车厢加强密封等简单改造后,快速升级为具备负压隔离功能的负压救护车。方法采用一体化设计,集成动力排风、空气高效过滤、紫外线杀菌、负压监测与报警等功能与一体。分别使用物理气溶胶和病毒气溶胶检测该装置的过滤效率;装置正常运行后,通过微压差传感器测量救护车病员室的负压值;通过测量装置的排风量计算救护车病员室的换气次数。结果该装置的过滤效率、救护车病员室的负压值、换气次数均达到国家卫生行业标准要求。结论该装置过滤效率高,体积小,功能集成化,安装方便,在全国范围内为呼吸道传染病疫情的防控提供了装备支撑,取得了显著的社会效益。     

Face seal leakage of half masks and surgical masks

The efficiency and face seal leakage characteristics of two half masks equipped with particle filters or gas filters, and of two surgical masks were studied by means of a test head connected to a breathing machine. Filtration and leakage were studied as a function of particle size over a diameter range of 0.3-10 micron with corn oil aerosol and an optical particle counter. The filtration efficiency of the filter materials was good, over 95%, for particles above 5 micron in diameter but great variation existed for smaller particles. The face seal leakage was manifested as decreased efficiency for large particles and also for total mass, while the particles in the micrometer range contained the major part of the test aerosol mass. The particle number efficiency diagrams obtained can be used both in filter material studies and in leak detection of valves or filter housings.     

Critical review of international standards for respiratory protective equipment - I. Respiratory protective equipment for particulate-laden atmospheres

The standards for respiratory protective equipment (R.P.E.) from eleven countries and standards organizations were grouped according to type as particulate removing, gas and vapor removing, airline (fresh air hose and compressed air types), and self-contained breathing apparatus (open circuit and closed circuit). Each group of standards was further divided into specification and performance requirements. This paper is one in a series of three that highlights and critically reviews international respirator standards; it deals specifically with R.P.E. for protection against particulate-laden atmospheres. Great Britain, Australia, European Committee for Standardization (CEN), France, South Africa, Italy, Spain, New Zealand, Scandinavia, Japan, and Germany have standards for R.P.E. against particulate-laden atmospheres. Tabular summaries and accompanying discussion of national requirements are presented in the following categories: solid and liquid aerosol removal efficiency, clogging, and rough usage. Large differences and some notable omissions exist among standards. For example, the protection capacity of the filter can be tested by using solid particulate or liquid challenge aerosols. The majority of the countries evaluate protection capacity using solid particulate aerosols, while the remainder use both solid and liquid or liquid aerosols only. Other differences in filter testing deal with the composition of the test aerosol and the characteristic of the filter measured. The initial penetration or the penetration of the filter as it is being loaded over a specified period of time can be measured. In the latter case penetration is averaged over the test period and the degree of protection is assessed only for that overall time period; information is not provided concerning the protection afforded by the filter in the earlier stages of use.     

用金黄色葡萄球菌气溶胶评价输液器进气器件细菌截留能力

 目的 设计气溶胶细菌截留试验系统，利用金黄色葡萄球菌气溶胶评价输液器进气器件空气过滤器的细菌截留能力。方法 将金黄色葡萄球菌混悬液稀释至10⁸ CFU/mL，利用气溶胶细菌截留试验系统生成气溶胶，对阳性对照支路以及5个生产厂家（A~E）的75个空气过滤器进行测试，采用薄膜过滤法收集液体撞击采样器的采样液，观察是否有菌生长并进行计数。结果 测试结束后，阳性对照支路和5个生产厂家A~D的12个批次60个样品的支路收集液均无菌生长，符合要求；生产厂家E 3个批次的15个样品支路收集液菌落数均>100 CFU，不符合要求。生产厂家E的空气过滤器材质为玻璃纤维，孔径为5 μm。结论 试验设计的气溶胶细菌截留试验系统成功截留输液器进气器件空气过滤器细菌。     

The liquid barrier filter: total protection against particulate contaminants

The design, construction, and operation of a new type of filter that eliminates particulate contaminants from a current of gas is described. It has a yield higher than that of any conventional filter or filtration system. It is believed that a liquid barrier filter provides the best possible protection in all cases where not even a small number of toxic particulates can be tolerated in an atmosphere.