Performance evaluation of filtering facepiece respirators using virus aerosols.

Physical penetration and infectivity penetration of adenovirus and influenza virus aerosols through respirators were measured to better characterize the effectiveness of filtering facepiece respirators against airborne virus. A physical penetration of 2%-5% was found. However, large sample-to-sample variation made it difficult to quantify the difference in physical penetration caused by the different virus aerosols. Infectivity penetration of adenovirus was much lower than physical penetration, indicating that the latter provides a conservative estimate for respirator performance.