What is BFE, and what does it measure?
BFE stands for Bacterial Filtration Efficiency. This test evaluates how well a respirator or surgical mask can prevent biological particles from being expelled by the wearer into the environment. Bioaerosol particles generated during the BFE test are “large,” on the order of 1 to 5 microns in size. For comparison, particles used for respirator filter efficiency tests are much smaller, approximately 0.3 microns in size. The BFE test is a relative indicator of the performance of a medical, surgical or patient care mask but the results cannot be compared to respirator certification filtration efficiency.
