Homemade Facemasks: Particle Filtration, Breathability, Fit, and Other Performance Characteristics

Details

• Personal Author:
  Grinshpun SA ; Reponen T ; Reutman SR ; Yermakov M
• Description:
  Homemade cloth masks and other improvised face coverings have become widespread during the COVID-19 pandemic driven by severe shortages of personal protective equipment. In this study, various alternative (mostly common household) materials, which have not traditionally been used in respiratory protective devices, were tested for particle filtration performance and breathability. Most of these materials were found of some-but rather limited-utility in facemasks. At a breathing flow rate of 30 L min-1, 17 out of 19 tested materials demonstrated collection efficiency below 50%; at 85 L min-1, only one material featured particle collection efficiency above 50%. Pressure drop values were mostly below 4 mm w.g. (observed in 89% of cases for the two flow rates), which provides comfortable breathing. Only for one fabric material (silk) tested at 85 L min-1 did the pressure drop reach 11 mm w.g. Based on these results, a three-layer facemask prototype was designed and fabricated comprised of the best performing materials. Additional tests were conducted to examine possible particle detachment/shedding from the materials used in the newly developed facemask, but no such phenomenon was observed. The prototype was evaluated on 10 human subjects using the standard OSHA-approved quantitative fit testing protocol. The mask protection level, determined as an adopted fit factor, was found to lie between that of the two commercial surgical/medical masks tested for comparison. A 10-cycle washing of the mask prototype lowered its collection efficiency across the particle size range; however, washing did not substantially affect mask breathability. The study revealed that although homemade masks offer a certain level of protection to a wearer, one should not expect them to provide the same respiratory protection as high-end commercial surgical/medical masks or-by any means-NIOSH-certified N95 filtering facepieces. [Description provided by NIOSH]
• Subjects:
  Communicable Diseases Occupational Health Particulate Matter Personal Protective Equipment Protective Clothing Respiratory Protective Devices Risk Assessment Safety
• Keywords:
  Author Keywords: COVID-19 Cloth Mask Face Covering Face Masks Filter Materials Filters Fit Fit Testing N95 Filtering Facepiece Respirators Particle Collection Efficiency Particulates Personal Protective Equipment PPE Protective Clothing Quantitative Risk Assessment Respiratory Protection Respiratory Protective Equipment Statistical Analysis

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  District of Columbia ; Ohio ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 6 ; Pennsylvania ; Texas
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  334-344
• Volume:
  18
• Issue:
  7
• NIOSHTIC Number:
  nn:20063033
• Citation:
  J Occup Environ Hyg 2021 Jul; 18(7):334-344
• Contact Point Address:
  W. Jon Williams, National Personal Protective Technology Laboratory (NPPTL), NIOSH/CDC 626, Cochrans Mill Road, Pittsburgh, PA 15236, USA
• Email:
  aun7@cdc.gov
• CAS Registry Number:
  Oxygen (CAS RN 7782-44-7)
• Federal Fiscal Year:
  2021
• Performing Organization:
  University of Cincinnati
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20260630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:90f9297714ef8958bd8aa7e9cbe4ae2cf68e54bd39561d8fa77d8d1e2e1d981d329247d47358f3574bbeffe2eded44b3a75d8bc9bc3f4af812ad249253ba2b56
• Download URL:
  https://stacks.cdc.gov/view/cdc/226163/cdc_226163_DS1.pdf
• File Type:
  [PDF - 1.56 MB ]