1.1 该测试方法用于评估医用口罩在小体积（~2mL）高速合成血液流的冲击下的渗透阻力。医用口罩 通过/失败 测定基于对合成血液渗透的视觉检测。 1.2 本试验方法不适用于所有形式或条件的血液传播病原体暴露。测试方法的使用者必须审查面部暴露的模式，并评估该测试方法在其特定应用中的适当性。 1.3 该测试方法主要用于测试成品医用口罩的性能。虽然该测试方法也可用于评估医用口罩中使用的材料或某些材料结构的性能，但重要的是要注意，成品医用口罩的性能可能会受到所用材料的相互作用及其组装方式的影响。 根据最终成品医用口罩的测试或从生产的医用口罩中提取的材料，结果可能会有所不同。 1.4 该测试方法没有解决可能影响医用口罩及其操作提供的整体保护的其他因素（如过滤效率和压降）。 1.5 该测试方法不涉及医用口罩材料的透气性或影响医用口罩呼吸舒适性的任何其他特性。该测试方法将医用口罩作为防护服进行评估。该测试方法不评估医用口罩在空气传播途径或防止沉积在医用口罩上的雾化体液渗透方面的性能。 1.6 以国际单位制或英寸磅单位表示的数值应单独视为标准。 每个系统中规定的值可能不是完全相等的；因此，每个系统应独立使用。将两个系统的值结合起来可能会导致不符合标准。每个系统中规定的压力值并不完全相等。然而，由于相应的速度在1以内 % 彼此的（请参见 X1.4.2 )，允许以任一单位报告结果。 1.7 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 该测试方法提供了一种评估医用口罩对合成血液渗透阻力的程序，有助于确定医用口罩的渗透阻力性能声明并对其性能进行排名。然而，该测试方法并未定义可接受的渗透阻力水平，因为该确定必须由每个负责的用户组织根据其自身的具体应用和条件进行。因此，当使用这种测试方法对医用口罩的性能进行索赔时，必须描述进行测试的具体条件。 5.2 医用口罩可用于抵抗血液、体液和其他潜在传染性物质的飞溅或飞溅造成的液体渗透。许多因素影响体液的润湿和渗透特性，例如流体的表面张力、粘度和极性，以及材料的结构和相对亲水性或疏水性以及口罩本身的设计。 血液和体液（不包括唾液）的表面张力范围约为0.042至0.060N/m。 6. 为了帮助模拟血液和体液的润湿特性，将合成血液的表面张力调整为接近该表面张力范围的下端。合成血液的表面张力为40±5 dyn/cm（0.040±0.005 N/m）。 5.3 合成血液混合物是用红色染料和增稠剂制备的，红色染料有助于视觉检测，增稠剂模拟血液的流动特性。合成血液不会总是复制真实血液和其他体液通过防护服材料的极性，从而复制润湿行为和随后的渗透。 5.4 在医疗过程中，血管偶尔会被刺破，导致高速血流冲击医用防护面罩。 冲击速度取决于几个因素，最重要的是患者的血压。其他因素包括穿刺的大小和与穿刺的距离。由于大穿刺时压力和速度会迅速下降，因此不使用大穿刺来模拟本试验中考虑的血液飞溅速度范围。此外，该测试方法基于医用口罩将非常靠近穿刺区域（在300mm或12英寸内）的假设。因此，该测试方法的使用基于选择适当的血压，找到相应的血流或冲击速度，并确定产生该血流速度的瓣膜时间，如所示 附录X1 . 5.4.1 平均人体血压通常在约10.7至16.0kPa（80至120mmHg）的范围内变化。 7. 在该测试方法中，医用口罩在对应于10的流速下进行测试。 7千帕、16.0千帕和21.3千帕（80毫米汞柱、120毫米汞柱和160毫米汞柱）。 5.5 该测试方法允许使用其他非标准测试压力、流速、流体体积和样本方向来评估符合特定应用的医用口罩渗透阻力。 5.6 此测试方法与测试方法不同 F1670/F1670M 通过向完整医用口罩样本的目标区域分配2 mL合成血液流，而试验方法 F1670/F1670M 涉及防护服样本与合成血液在一小时内的连续接触。试验方法中暴露一分钟 F1670/F1670M 流体静压为13.8 kPa[2.0 psig]。试验方法 F1670/F1670M 与试验方法一起用于初步评估防护服对合成血液的渗透阻力 F1671/F1671M 使用微生物挑战。这两种程序都旨在评估防护服是否有可能在压力下长时间接触血液或其他体液。 5.7 该测试方法的使用者必须意识到，在医用口罩对合成血液渗透的抵抗力的提高和作为医用口罩透气性指标的口罩材料的压降之间存在一定的权衡。一般来说，医用口罩的合成血液渗透阻力的增加会导致与个人佩戴者相同设计和贴合度的医用口罩的压降增加或透气性降低。 5.8 该测试方法将医用口罩作为防护服进行评估，而不将医用口罩评估为呼吸器。如果需要为佩戴者提供呼吸保护，NIOSH- 必须使用经过认证的呼吸器。如果有必要，此测试方法可用于评估呼吸器对合成血液渗透的抵抗力。 5.9 该试验方法涉及在相对高湿度环境（85±5 % 21±5时的相对湿度 °C[70±10 °F]），以模拟佩戴者通过面罩呼吸产生高湿度条件时的使用条件。这种预处理不考虑医用面罩内层的饱和度。但是，如 5.10 是允许的。专业医疗保健提供者建议，当呼吸或接触其他液体时出现饱和时，应更换医用口罩。 5.10 物理、化学和热应力降解之前的测试可能会对保护屏障的性能产生负面影响，这可能会导致错误的安全感。 考虑评估一次性产品储存条件和保质期的影响，以及可重复使用产品清洗和消毒的影响的测试。防护服的完整性在使用过程中偶尔会受到弯曲和磨损等影响。 8. 还可能的是，被诸如酒精和汗液的污染物预润湿也会损害防护服的完整性。如果这些条件令人担忧，则按照代表预期使用条件的适当预处理技术，评估防护服对合成血液渗透的性能。 5.11 虽然该测试方法涉及在特定测试条件下对医用口罩抗合成血液渗透性的定性测定，但也可以将该测试方法用作质量控制或保证程序。 5.12 如果此程序用于质量控制，则对较大的数据集进行适当的统计设计和分析，以确定所需的待测试样本数量。以这种方式进行的抽样有助于建立有关产品性能的置信限。所选择的抽样计划或统计方法应由相关负责机构指定或批准。可接受抽样计划的示例见参考文献，如ISO 2859系列属性检验标准和ANSI/ASQC Z1.4和ANSI/ASQC Q3。 注1: 验收抽样计划的选择指南可在参考文献（如ISO/TR 8550-1和ISO/TR 8550-2）中找到。 注2: 根据测试目的，相关负责机构可以是第一方、第二方或第三方。有关验收抽样计划中负责机构的更多信息（包括示例、职责和职能），请参阅ISO 2859等参考资料- 1. 5.13 如果在使用这种测试方法进行商业货物验收测试时，由于报告结果的差异而产生争议，则在买方和供应商之间进行比较测试，以确定他们的实验室之间是否存在统计偏差。建议提供适当的统计协助以调查偏差。至少，取一组尽可能均匀的试样，这些试样来自所讨论类型的许多产品。将相等数量的试样随机分配到每个实验室进行测试。在测试开始前，使用未配对数据的非参数测试和双方选择的可接受概率水平，比较两个实验室的平均结果。如果发现偏差，必须找到并纠正其原因，或者买方和供应商必须同意在考虑已知偏差的情况下解释未来的测试结果。

1.1 This test method is used to evaluate the resistance of medical face masks to penetration by the impact of a small volume (~2 mL) of a high-velocity stream of synthetic blood. Medical face mask pass/fail determinations are based on visual detection of synthetic blood penetration. 1.2 This test method does not apply to all forms or conditions of blood-borne pathogen exposure. Users of the test method must review modes for face exposure and assess the appropriateness of this test method for their specific application. 1.3 This test method is primarily intended to address the performance of finished medical face masks. While this test method may also be used to assess performance of materials or certain material constructions used in medical face masks, it is important to note the performance of finished medical face masks may be impacted by the interaction of the materials used and how they have been assembled. Results can differ depending on testing a final finished medical face mask or materials taken from manufactured medical face masks. 1.4 This test method does not address other factors with the potential to affect the overall protection offered by the medical face mask and its operation (such as filtration efficiency and pressure drop). 1.5 This test method does not address breathability of the medical face mask materials or any other properties affecting the ease of breathing through the medical face mask. This test method evaluates medical face masks as an item of protective clothing. This test method does not evaluate the performance of medical face masks for airborne exposure pathways or in the prevention of the penetration of aerosolized body fluids deposited on the medical face mask. 1.6 The values stated in SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. The pressure values stated in each system are not exact equivalents. However, as the corresponding velocities are within 1 % of each other (see X1.4.2 ), reporting of the results in either units is permitted. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This test method offers a procedure for evaluating medical face mask resistance to synthetic blood penetration that is useful in establishing claims for penetration resistance performance of medical face masks and ranking their performance. However, this test method does not define acceptable levels of penetration resistance because this determination must be made by each responsible user organization based on its own specific application and conditions. Therefore, when using this test method to make claims for the performance of medical face masks, the specific conditions under which testing is conducted must be described. 5.2 Medical face masks may be intended to resist liquid penetration from the splatter or splashing of blood, body fluids, and other potentially infectious materials. Many factors affect the wetting and penetration characteristics of body fluids, such as surface tension, viscosity, and polarity of the fluid, as well as the structure and relative hydrophilicity or hydrophobicity of the materials and the design of the mask itself. The surface tension range for blood and body fluids (excluding saliva) is approximately 0.042 to 0.060 N/m. 6 To help simulate the wetting characteristics of blood and body fluids, the surface tension of the synthetic blood is adjusted to approximate the lower end of this surface tension range. The resulting surface tension of the synthetic blood is 40 ± 5 dyn/cm (0.040 ± 0.005 N/m). 5.3 The synthetic blood mixture is prepared with a red dye to aid in visual detection and a thickening agent to simulate the flow characteristics of blood. The synthetic blood will not always duplicate the polarity, and thus the wetting behavior and subsequent penetration, of real blood and other body fluids through protective clothing materials. 5.4 During a medical procedure, a blood vessel is occasionally punctured, resulting in a high-velocity stream of blood impacting a protective medical face mask. The impact velocity depends on several factors, the most important being the blood pressure of the patient. Other factors include the size of the puncture and distance from the puncture. Because the pressure, and thus velocity drops quickly with large punctures, large punctures were not used to model the range of blood splatter velocities considered in this test. Furthermore, this test method is based on the assumption that the medical face mask will be in close proximity (within 300 mm or 12 in.) to the puncture area. The use of this test method is, therefore, based on selecting an appropriate blood pressure, finding the corresponding stream or impact velocity, and determining the valve time to create that stream velocity as shown in Appendix X1 . 5.4.1 The mean human blood pressure generally varies over a range of about 10.7 to 16.0 kPa (80 to 120 mmHg). 7 In this test method, medical face masks are tested at stream velocities corresponding to 10.7 kPa, 16.0 kPa, and 21.3 kPa (80 mmHg, 120 mmHg, and 160 mmHg). 5.5 This test method permits the use of other non-standard test pressures, stream velocities, fluid volumes, and specimen orientations for evaluating medical face mask penetration resistance consistent with specific applications. 5.6 This test method differs from Test Method F1670/F1670M by dispensing a stream of 2 mL of synthetic blood against the target area of a complete medical mask specimen, whereas Test Method F1670/F1670M involves the continuous contact of a specimen of protective clothing with synthetic blood over the period of an hour. One minute of the exposure in Test Method F1670/F1670M is at hydrostatic pressure of 13.8 kPa [2.0 psig]. Test Method F1670/F1670M is used for preliminary evaluation of protective clothing penetration resistance to synthetic blood in conjunction with Test Method F1671/F1671M that uses a microbiological challenge. Both procedures are intended for assessment of protective clothing which has the potential to contact blood or other body fluids for extended periods of time, and under pressure. 5.7 Users of this test method must realize that certain tradeoffs exist between improved resistance of medical face masks to penetration by synthetic blood and in pressure drop across mask materials as an indicator of medical face mask breathability. In general, increasing synthetic blood penetration resistance for medical face masks results in increasing pressure drop or reduced breathability for medical face masks of the same design and fit of the individual wearer. 5.8 This test method evaluates medical face masks as an item of protective clothing and does not evaluate medical face masks as respirators. If respiratory protection for the wearer is needed, a NIOSH-certified respirator must be used. This test method is useful to evaluate the resistance of a respirator to penetration by synthetic blood, if warranted. 5.9 This test method involves the preconditioning of specimen medical face masks in a relatively high humidity environment (85 ± 5 % relative humidity at 21 ± 5 °C [70 ± 10 °F]) to simulate the conditions of use when the wearer creates high humidity conditions by breathing through the mask. This preconditioning does not account for saturation of the interior medical face mask layer. However, additional pretreatment techniques in conjunction with this test method as described in 5.10 are permitted. Professional healthcare providers recommend that medical face masks be replaced when saturation occurs from breathing or from contact with other liquids. 5.10 Testing prior to degradation by physical, chemical, and thermal stresses which could negatively impact the performance of the protective barrier could lead to a false sense of security. Consider tests which assess the impact of storage conditions and shelf life for disposable products, and the effects of laundering and sterilization for reusable products. The integrity of the protective clothing is occasionally compromised during use by such effects as flexing and abrasion. 8 It is also possible that pre-wetting by contaminants such as alcohol and perspiration also compromises the integrity of the protective clothing. If these conditions are of concern, evaluate the performance of protective clothing for synthetic blood penetration following an appropriate pretreatment technique representative of the expected conditions of use. 5.11 While this test method involves a qualitative determination of the medical face mask resistance to penetration by synthetic blood under specific test conditions, it is possible to use this test method as a quality control or assurance procedure. 5.12 If this procedure is used for quality control, perform proper statistical design and analysis of larger data sets to determine the required number of specimens to be tested. Sampling conducted in this way helps to establish confidence limits concerning product performance. The sampling plan or statistical approach selected should be designated or approved by the relevant responsible authority. Examples of acceptable sampling plans are found in references such as the ISO 2859 series of standards for inspection by attributes and ANSI/ASQC Z1.4 and ANSI/ASQC Q3. Note 1: Guidance on the selection of acceptance sampling plans can be found in references such as ISO/TR 8550-1 and ISO/TR 8550-2. Note 2: Subject to the purpose of testing the relevant responsible authority may be a first, second, or third party. Further information about responsible authorities in the context of acceptance sampling plans (including examples, duties, and functions) can be found in references such as ISO 2859-1. 5.13 In the case of a dispute arising from differences in reported results when using this test method for acceptance testing of commercial shipments, conduct comparative tests between the purchaser and supplier to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for investigation of bias. At minimum, take a group of test specimens which are as homogeneous as possible and which are from a lot of the product of the type in question. Randomly assign test specimens in equal numbers to each laboratory for testing. Compare the average results from the two laboratories using a non-parametric test for unpaired data and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.