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Air-Purifying Respirator

The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform

Alex G. Pappas – 1st expert on this subject based on the ideXlab platform

  • Domestic Preparedness Program: Protection Factor Testing of the Se-Shield Suit with the SE400 Powered Air Purifying Respirator (PAPR)
    , 2004
    Co-Authors: Adam D. Seiple, Alex G. Pappas

    Abstract:

    Abstract : Intact suit was challenged with corn oil to simulate a biological or chemical aerosol. Protection factors were determined for the suit.

  • Protection Factor Testing of the 3M Breathe Easy (BE-10) Powered Air Purifying Respirator (PAPR)
    , 2003
    Co-Authors: Adam D. Seiple, Alex G. Pappas

    Abstract:

    Abstract : This report describes the results of the performance testing of the 3M Breathe Easy (BE-10) Powered Air Purifying Respirator. A series of tests were performed to determine the corn-oil protection factors using human subjects.

  • Domestic Preparedness: Phase 2 Sarin Vapor Challenge and Corn Oil Protection Factor (PF) Testing of Commercial Powered Air Purifying Respirator (PAPR) Systems and Cartridges
    , 2002
    Co-Authors: Lee E. Campbell, Ray Lins, Alex G. Pappas

    Abstract:

    Abstract : Results of performance testing of commercial powered air purifying Respirator (PAPR) systems and cartridges are described. Three series of tests were performed: (1) breakthrough time determinations of cartridges against Sarin (GB); (2) GB vapor penetration determination of entire PAPR systems using manikin headform and simulated breathing; and (3) corn-oil protection factor determinations of PAPR systems using human subjects. Results indicate that cartridges provide complete penetration resistance against 200 mg/m(3) GB challenge concentrations for 60 min, but unacceptably high levels of GB vapor and corn oil aerosol may penetrate into the breathing zone of the PAPRs.

Kaarle J. Hämeri – 2nd expert on this subject based on the ideXlab platform

  • Workplace performance of a loose-fitting powered air purifying Respirator during nanoparticle synthesis
    Journal of Nanoparticle Research, 2020
    Co-Authors: Antti J. Koivisto, Mikko Aromaa, Ismo K. Koponen, Wouter Fransman, Keld A. Jensen, Jyrki M. Mäkelä, Kaarle J. Hämeri

    Abstract:

    Nanoparticle (particles with diameter ≤100 nm) exposure is recognized as a potentially harmful size fraction for pulmonary particle exposure. During nanoparticle synthesis, the number concentrations in the process room may exceed 10 × 106 cm−3. During such conditions, it is essential that the occupants in the room wear highly reliable high-performance Respirators to prevent inhalation exposure. Here we have studied the in-use program protection factor (PPF) of loose-fitting powered air purifying Respirators, while workers were coating components with TiO 2 or Cu x O y nanoparticles under a hood using a liquid flame spray process. The PPF was measured using condensation particle counters, an electrical low pressure impactor, and diffusion chargers. The room particle concentrations varied from 4 × 106 to 40 × 106 cm−3, and the count median aerodynamic diameter ranged from 32 to 180 nm. Concentrations inside the Respirator varied from 0.7 to 7.2 cm−3. However, on average, tidal breathing was assumed to increase the Respirator concentration by 2.3 cm−3. The derived PPF exceeded 1.1 × 106, which is more than 40 × 103 times the Respirator assigned protection factor. We were unable to measure clear differences in the PPF of Respirators with old and new filters, among two male and one female user, or assess most penetrating particle size. This study shows that the loose-fitting powered air purifying Respirator provides very efficient protection against nanoparticle inhalation exposure if used properly. © 2015, Springer Science+Business Media Dordrecht.

  • Workplace performance of a loose-fitting powered air purifying Respirator during nanoparticle synthesis
    Journal of Nanoparticle Research, 2015
    Co-Authors: Antti J. Koivisto, Mikko Aromaa, Ismo K. Koponen, Wouter Fransman, Keld A. Jensen, Jyrki M. Mäkelä, Kaarle J. Hämeri

    Abstract:

    Nanoparticle (particles with diameter ≤100 nm) exposure is recognized as a potentially harmful size fraction for pulmonary particle exposure. During nanoparticle synthesis, the number concentrations in the process room may exceed 10 × 10^6 cm^−3. During such conditions, it is essential that the occupants in the room wear highly reliable high-performance Respirators to prevent inhalation exposure. Here we have studied the in-use program protection factor (PPF) of loose-fitting powered air purifying Respirators, while workers were coating components with TiO_2 or Cu_ x O_ y nanoparticles under a hood using a liquid flame spray process. The PPF was measured using condensation particle counters, an electrical low pressure impactor, and diffusion chargers. The room particle concentrations varied from 4 × 10^6 to 40 × 10^6 cm^−3, and the count median aerodynamic diameter ranged from 32 to 180 nm. Concentrations inside the Respirator varied from 0.7 to 7.2 cm^−3. However, on average, tidal breathing was assumed to increase the Respirator concentration by 2.3 cm^−3. The derived PPF exceeded 1.1 × 10^6, which is more than 40 × 10^3 times the Respirator assigned protection factor. We were unable to measure clear differences in the PPF of Respirators with old and new filters, among two male and one female user, or assess most penetrating particle size. This study shows that the loose-fitting powered air purifying Respirator provides very efficient protection against nanoparticle inhalation exposure if used properly.

Gerry O. Wood – 3rd expert on this subject based on the ideXlab platform

  • Estimating Reusability of Organic Air-Purifying Respirator Cartridges
    Journal of Occupational and Environmental Hygiene, 2011
    Co-Authors: Gerry O. Wood, Jay L. Snyder

    Abstract:

    Reuse of organic vapor Air-Purifying Respirator cartridges after a job or shift can provide economy and energy savings. However, standards and manufacturers’ guidance discourage reuse, presumably due to a lack of quantitative objective exposure and use information. Storage and simulated reuse laboratory studies and modeling have been done to provide such information. Two important parameters of breakthrough curves, midpoint time (related to adsorption capacity) and midpoint slope (related to adsorption rate), have been shown to be unchanged during storage for reuse. Extrapolations to smaller breakthrough concentrations and times can be made from this reference breakthrough and time. Significant step increases in breakthrough concentration upon cartridge reuse have been observed in some cases. Values of immediate breakthrough concentrations upon reuse (IBURs) have been measured and correlated. The Dubinin/Radushkevich adsorption isotherm equation has been used to estimate maximum IBURs, which depend on man…

  • Estimating service lives of Air-Purifying Respirator cartridges for reactive gas removal.
    Journal of Occupational and Environmental Hygiene, 2005
    Co-Authors: Gerry O. Wood

    Abstract:

    A mathematical model has been developed to estimate service lives of Air-Purifying Respirator cartridges that remove gases reactively from flowing air. Most gases, because of their high volatility and low polarizability, are not effectively removed by physical adsorption on activated carbon. Models previously developed for toxic organic vapors cannot estimate service lives of cartridges for toxic gases. Often, an activated carbon is impregnated with a chemical to enhance gas removal by chemical reaction(s). The kinds of reactions, types and amounts of impregnants, and effects of the presence of water vary; therefore, the model requires user inputs of gas capacity and water effect parameters. Ideally, these should be available from manufacturers of the cartridges. If they are not, they can be extracted from measured breakthrough times using this model. The key to this model is the observation that adsorption rates of gases can be adequately quantified by the same correlations that have been reported for or…

  • Estimating Service Lives of Organic Vapor Cartridges II: A Single Vapor at All Humidities
    Journal of Occupational and Environmental Hygiene, 2004
    Co-Authors: Gerry O. Wood

    Abstract:

    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.