Interpretation of Inhalation Airflow Measurements for Respirator Design and Testing

ecent studies and much debate have focused on quantifying the airflow requirements of respirator users, particularly under conditions of very high to maximal work rates. It is often assumed that respirators and their components must be tested at flow rates that closely match these measurements to assure protection to users. This overly simplified assumption ignores the differences between laboratory tests and the workplace conditions in which respirators are used. While respirators and their components could be designed to comply with any airflow requirement, any change in performance requirements must first be evaluated to ensure it does not decrease workplace performance or user comfort. This paper suggests appropriate use of airflow measurements in setting respirator performance criteria and evaluating user protection. Available data do not suggest a need for change in testing criteria at this time. There is no indication that respirators that meet current U.S. approval criteria or substantially similar tests need performance enhancement to provide acceptable protection.