NPPTL intends to purchase a test equipment to conduct ASTM F2101 Bacterial Filtration Efficiency (BFE) which measures the number of infectious agents retained by the mask. The ratio of the upstream (air mixture entering the mask) bacterial challenge to downstream (air mixture leaving the mask) concentrations determines the filtration efficiency of the medical face mask materials. The Staphylococcus aureus bacteria is used as the challenging microorganism where a suspension of the bacteria is aerosolized using a nebulizer and released through the mask to evaluate the filtration efficiency. The challenge particles are not charge neutralized for testing. The bacterial aerosol is drawn through the test sample at the flow rate of 28.3 L/min which is like human breathing. The downstream bacterial residuals are collected and counted for viable particles using a six-stage cascade impactor which utilizes six sequential agar plates. A positive control without a test filter sample clamped into the system is used to determine the number of viable particles being used in each test. A negative control with no bacteria in the airstream is performed to determine the background challenge in the glass aerosol chamber prior to testing. NPPTL intends to use this test device to measure the bacterial filtration efficiency of several Personal Protective Equipment, including gowns, masks, and respirators. Since NIOSH intends to test protective clothing, flow rate adjustments in addition to standard equipment features, where the flow rate can be set to anywhere between 0 to 28.3 L/min, are required. The testing equipment should be a standalone, plug-in device placed into a closed chamber, which provides a great advantage over open systems due to the sterility requirement of the bacterial filtration efficiency test. The test equipment should have two columns for testing. Please see SF18 Request for Quotations in the attachment section.