Determination of organic vapor respirator cartridge variability in terms of degree of activation of the carbon and cartridge packing density.
Trout-D; Breysse-PN; Hall-T; Corn-M; Risby-T
Am Ind Hyg Assoc J 1986 Aug; 47(8):491-496
The variability among three commercially available organic vapor respirator cartridges was determined in terms of amount and packing density of carbon, particle size distribution, and degree of carbon activation. Carbon-tetrachloride adsorption isotherms were measured using the elution chromatographic technique; isotherms were transformed into characteristic curves using the Dubin Radushkevich (D/R) equations. Cartridges from three manufacturers were purchased commercially as representative of cartridges any respirator user might purchase. The mean packing densities of the cartridges varied from 0.40 grams/cubic centimeter (g/cm3) to 0.52g/cm3. The median particle sizes varied from 1.20 to 1.28 millimeters (mm). Variability between different lots of cartridges was compared with the variability present within any one lot by the analysis of variance (ANOVA); 64 percent of the total variability was attributable to the differences between lots, while 22 percent was attributable to differences between cartridges of one lot. Variation between lots of individual manufacturers was sometimes statistically significant. Cartridges from one supplier contained 20 percent more carbon than cartridges from the other two. The authors conclude that cartridges may vary significantly in the mass of carbon they contain, in packing density, and degree of carbon activation. Particle size distributions were similar, with median particle sizes ranging from 1.20 to 1.28 mm. In the five groups of cartridges examined, the difference in particle size should have a negligible effect on service life. The most important parameter in terms of packing density is probably the mass of carbon per cartridge.
NIOSH-Grant; NIOSH-Publication; Air-purifying-respirators; Air-purification; Toxic-vapors; Organic-vapors; Organic-chemicals
American Industrial Hygiene Association Journal
Environmental Health Sciences Johns Hopkins University 615 North Wolfe Street Baltimore, MD 21205