The key to ensuring that rational respirator technology solutions are possible and acceptable to the user community is the knowledge that each option has a sound scientific basis. Historical mask wear human performance research offers useful, albeit limited, insights on the relationships between design parameters and performance. The purposes of the current task were to review and revise the existing human performance capabilities and mask design parameters databases and to derive new algorithms to more accurately define human performance capabilities related to respirator wear. The results reaffirm that much of the basic psychophysiological data needed to enhance respirator design requirements remains elusive. The main data gaps across all performance capabilities include little or no knowledge concerning the relationships among respirator design components and performance and the impacts of design parameters on task performance across different work intensities. The impacts of mask design on subjective comfort and subsequent task performance is the capability area with the least amount of reliable information. In this regard, research needs to continue to advance the knowledge base to ensure that next generation respirator designs can be based on robust human factors data.