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Evaluation of five decontamination methods for filtering facepiece respirators.
Viscusi DJ; Bergman MS; Eimer BC; Shaffer RE
Ann Occup Hyg 2009 Nov; 53(8):815-827
Concerns have been raised regarding the availability of National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) during an in- fluenza pandemic. One possible strategy to mitigate a respirator shortage is to reuse FFRs following a biological decontamination process to render infectious material on the FFR inactive. However, little data exist on the effects of decontamination methods on respirator integrity and performance. This study evaluated five decontamination methods [ultraviolet germicidal irradiation (UVGI), ethylene oxide, vaporized hydrogen peroxide (VHP), microwave oven irradiation, and bleach] using nine models of NIOSH-certified respirators (three models each of N95 FFRs, surgical N95 respirators, and P100 FFRs) to determine which methods should be considered for future research studies. Following treatment by each decontamination method, the FFRs were evaluated for changes in physical appearance, odor, and laboratory performance (filter aerosol penetration and filter airflow resistance). Additional experiments (dry heat laboratory oven exposures, off-gassing, and FFR hydrophobicity) were subsequently conducted to better understand material properties and possible health risks to the respirator user following decontamination. However, this study did not assess the efficiency of the decontamination methods to inactivate viable microorganisms. Microwave oven irradiation melted samples from two FFR models. The remainder of the FFR samples that had been decontaminated had expected levels of filter aerosol penetration and filter airflow resistance. The scent of bleach remained noticeable following overnight drying and low levels of chlorine gas were found to offgas from bleach-decontaminated FFRs when rehydrated with deionized water. UVGI, ethylene oxide (EtO), and VHP were found to be the most promising decontamination methods; however, concerns remain about the throughput capabilities for EtO and VHP. Further research is needed before any specific decontamination methods can be recommended.
Air-conditioning-equipment; Air-contamination; Air-filters; Air-purification; Air-purifying-respirators; Air-quality; Air-quality-control; Air-quality-measurement; Air-quality-monitoring; Bacterial-disease; Bacterial-infections; Biohazards; Biomechanical-engineering; Equipment-design; Equipment-reliability; Exposure-assessment; Exposure-levels; Exposure-methods; Face-masks; Inhalation-studies; Occupational-exposure; Occupational-health; Personal-protective-equipment; Protective-equipment; Protective-measures; Pulmonary-system; Qualitative-analysis; Quality-control; Respiratory-equipment; Respiratory-hypersensitivity; Respiratory-infections; Respiratory-irritants; Respiratory-protective-equipment; Sanitation-engineering; Work-analysis; Workplace-studies; Work-practices; Author Keywords: decontamination; filtering facepiece respirator; healthcare workers; N95 respirator; pandemic influenza; respirator reuse
Ronald E. Shaffer, National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236
Issue of Publication
Healthcare and Social Assistance
Annals of Occupational Hygiene
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division