Respirator Cartridge Study Using Organic-Vapor Mixtures

The performance of respirator cartridges was measured during challenge by organic-vapor mixtures. All cartridges were tested in pairs under carefully controlled conditions of mass flow, temperature and relative humidity. Five chemical compounds were used during the testing: methyl ethyl ketone, isopropyl alcohol, hexane, n-butyl acetate and ethyl benzene. Cartridges were challenged by a single compound first at 1000 and then at 2000 ppm (by volume) concentration, under a standard flow of 40 Lpm. Every challenge was performed separately at 50% and then at 85% relative humidity. The authors chose the high concentration of each single-component challenge to equal the arithmetic total concentration of the five different two-component mixtures that were subsequently tested. The chemical concentrations were monitored upstream of the cartridges by infrared analysis and downstream by gas chromatography. The results showed that the observed breakthrough times for most of the mixture components were similar to those times measured for each single component at its high concentration.