Respirator Filter Efficiency Testing Against Particulate and Biological Aerosols Under Moderate to High Flow Rates

摘要

The growing terrorism threat associated with biological and chemical agents presents a challenge to emergency responders, healthcare workers, and the civilian population. Currently, National Institute for Occupational Safety and Health (NIOSH)-approved respirators are used in various workplace settings to provide protection against harmful aerosols. The primary objective of this project was to evaluate and compare the aerosol filtration performance of NIOSH- approved respirator filters with non-biological (inert) and biological test aerosols under breather flow rates associated with high work rates. The inert test challenges consisted of solid and oil aerosols having nominal diameters ranging from 0.02 to 3.02 micrometers, spanning the spectrum of potential biological threat agents. As expected, penetration of submicron aerosols was found to increase under increased cyclic and constant flow conditions. The magnitude and significance of this increase was dependent on the specific filter type and design. The most penetrating particle size was generally between 0.1 and 0.2 micrometers for the P100 filters and 0.05 and 0.10 micrometers for the N95 filters. Inert aerosols of similar aerodynamic diameter were shown to provide a reasonable estimate of performance against the biological aerosols tested.