ABSTRACT
This chapter provides a comprehensive description of issues related to the selection of respiratory protective devices against biological hazards and testing methods confirming their protective properties. Particular emphasis is placed on the phenomenon of microbial growth in filtering materials of such devices.
Legal acts in force in the European Union (EU) and the United States are discussed, considering obligations of manufacturers and users of the equipment. The characteristics of different types of filtering respiratory protective devices are presented. The division into protection classes, as well as basic design solutions for filters and filtering half masks, are considered.
Results of the most important works concerning filtration of biological and non-biological particles are discussed with respect to selection of appropriate measurement method and microorganism type for the assessment of filtration efficiency. Evidence is presented to demonstrate that even short-term use of some filtering respiratory protective devices can lead to rapid microbial growth or even development of biofilm in such devices. It is shown that much like microclimate parameters (elevated temperature and high humidity), the presence of organic dust on filtering material also constitutes a factor affecting survivability of microorganisms, which may pose additional hazard to workers.
