Significance and Use 5.1 This test method measures the initial filtration efficiency of materials used in medical face masks by sampling representative volumes of the upstream and downstream latex aerosol concentrations in a controlled airflow chamber. 5.2 This test method provides specific test techniques for both manufacturers and users to evaluate materials when exposed to aerosol particle sizes between 0.1 and 5.0 μm. 5.2.1 This test method establishes a basis of efficiency comparison between medical face mask materials. 5.2.2 This test method does not establish a comprehensive characterization of the medical face mask material for a specific protective application. 5.3 This test method does not assess the overall effectiveness of medical face masks in preventing the inward leakage of harmful particles. 5.3.1 The design of the medical face mask and the integrity of the seal of the medical face mask to the wearer’s face are not evaluated in this test. 5.4 This test method is not suitable for evaluating materials used in protective clothing for determining their effectiveness against particulate hazards. 5.4.1 In general, clothing design is a significant factor which must be considered in addition to the penetration of particulates.Scope 1.1 This test method establishes procedures for measuring the initial particle filtration efficiency of materials used in medical facemasks using monodispersed aerosols. 1.1.1 This test method utilizes light scattering particle counting in the size range of 0.1 to 5.0 μm and airflow test velocities of 0.5 to 25 cm/s. 1.2 The test procedure measures filtration efficiency by comparing the particle count in the feed stream (upstream) to that in the filtrate (downstream). 1.3 The values stated in SI units or in other units shall be regarded separately as standard. The values stated in each system must be used independently of the other, without combining values in any way. 1.4 The following precautionary caveat pertains only to the test methods portion, Section 10, of this specification. 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 and health practices and determine the applicability of regulatory limitations prior to use. 1.5 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.
