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Estimating service lives of organic vapor cartridges II: a single vapor at all humidities.
J Occup Environ Hyg 2004 Jul; 1(7):472-492
A widely used equation model for estimating service lives of organic vapor air-purifying respirator cartridges has been updated with more recent research results. It has been expanded to account for effects of high relative humidities. Adsorption capacity competition between water vapor and organic vapor is largely explained by mutual exclusion of adsorption volume of the activated carbon. The Dubinin/Radushkevich equation is used to describe the adsorption isotherms of both water and organic vapors. Effects of relative humidity and adsorbed water on adsorption rates are described by an empirical correlation with breakthrough times. The dynamic natures of adsorption and competition are incorporated using an expanding zone model with displaced water rollup. The complete model has been tested and verified with published and unpublished data from many sources.
Organic-vapors; Models; Air-purifying-respirators; Air-purifiers; Air-purification; Respirators; Respiration; Humidity; Author Keywords: cartridge; humidity; organic vapor; respirator; service life
Gerry Wood, Industiral Hygiene and Safety Group, Mail Stop K-486, Los Alamos National Laboratory, Los Alamos, NM 87545
Issue of Publication
Journal of Occupational and Environmental Hygiene
Page last reviewed: March 11, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division