Abstract

Respiratory protection is used to protect workers when it is impossible to eliminate contaminants at their source. Protection against organic vapours, one of the major classes of occupational contaminants, most commonly takes the form of masks equipped with chemical cartridges. However, users are rarely aware of the useful service-life of the cartridges.

This project therefore developed a system by which cartridge service-life may be predicted in the laboratory. The evaluation was based on a simple mathematical model and used an exposure-generating system capable of simulating exposure conditions, a respiratory simulator capable of cyclical or continuous operation, a sampling/analytical sub-system, and a data acquisition/analysis sub-system. Using this test bed, the service-life of cartridges was determined for each of four organic vapours found in the work environment. However, these evaluations are valid only for cases involving single exposures to any one of these four vapours, and cannot be extrapolated to mixed exposures. In addition, certain storage conditions, particularly the humidity level and presence of contaminants, can adversely affect cartridge performance and decrease the reliability of the service-life predictions.