Material-Level Evaluation of Particulate Filtration Efficiency (PFE)

Sioutas Particle Impactor

TPACC has devolved a new material-level assessment of particulate filtration efficiency for  materials that could be applied for mask particulate filtration. This technique was created as a screening tool to distinguish the performance of materials that are presently being applied for mask filtration purposes.

The test method uses a altered Sioutas Particle Impactor to hold the material specimen in place during testing and has the ability to test single and multiple layers. Presently, this examination counts the up and downstream of atmosphere particles and is measured at six size ranges: 0.3, 0.5, 1, 2, 5, and 10 μm. Duration of each test is 1 minute with 3 series of testing per specimen.

The nature of this assessment is to acquire fast, efficient, and repeatable results that can be used as an initial screening for assessment of material particulate filtration efficiency.

Introductory material-level testing has revealed that in environmental conditions, particulate filtration efficiency using N95 material specimens remains the gold standard for personal protective appliance (PPA). Alongside this baseline specimen,three other specimens were tested to distinguish the material’s particulate filtration efficiency performance. These comprised a standard surgical mask, coffee filters (3 layers), and plain cotton sheeting (4 layers).

Choice of these material samples were based on the favour and convenience to the common public in response to the COVID-19 pandemic. The graph focuses on the initial data based of introductory tests used to screen the material specimens. At about 0.3 microns, the % Particulate Filtration  Efficiency (%PFE) can be examined with each material specimen assessment.