Evaluation of Rigidity of Surgical N95 Respirators Using a Manikin-System: A Pilot Study

Details

• Personal Author:
  Niezgoda G ; Rengasamy S
• Description:
  Background: Surgical N95 respirators are devices certified by the National Institute for Occupational Safety and Health (NIOSH) and also cleared by the Food and Drug Administration (FDA) as a medical device. They are commonly used in healthcare settings to provide protection from infectious aerosols, as well as, bodily fluid sprays and splashes. It is hypothesized based on design, some models may change their shape significantly (i.e., collapse) during heavy breathing, which may allow the device to touch the wearer's face. Concerns have been raised that droplets of infectious biological fluids may reach the inner layer of surgical N95 respirators leading to the transfer of microorganisms to the oronasal facial region upon collapse. Unfortunately, little data currently exists on respirator rigidity testing or its relation to efficacy. The objective of this study was to develop and optimize a manikin-based test system to evaluate respirator rigidity. Methods: Six surgical N95 models of three different designs (cup-shaped, flat fold and trifold) were tested at two different environmental conditions on the NIOSH medium headform. Rigidity evaluation was performed at 50% relative humidity (RH) and 22 degrees C, and at approx. 100% RH and 33 degrees C at 40, 50, and 60 L/min breathing flow rates. Facial contact secondary to shape change was assessed by coating the inner layer of the surgical N95 respirators with a fluorescent tracer and its transfer to the manikin face. Results: The results showed that the cup-shaped models were rigid and resistant to shape change at both environmental conditions and all flow rates. In contrast, the flat fold models and trifold models showed significant changes with rigidity, at higher breathing flow rates and higher RH and temperature conditions. The flat fold models showed transfer of the fluorescent tracer to the manikin face at higher RH and breathing rates, confirming a change in rigidity. Conclusions: The results from the study suggest that the manikin-based test system designed for the purposes of this study can be used to evaluate respirator rigidity. [Description provided by NIOSH]
• Subjects:
  Air Movements Health Care Facilities Workforce And Services Humidity Occupational Health Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety Temperature
• Keywords:
  Air Flow Author Keywords: Surgical N95 Respirator Breathing Equipment Design Equipment Reliability Equipment Testing Face Masks Face Shields Fluid Penetration Fluids Fluorescence Tracer Medical Equipment N95 Filtering Facepiece Respirators Performance Capability Performance Tests Personal Protective Equipment PPE Relative Humidity Respirators Respiratory Protection Respiratory Protective Equipment Rigidity Surgical Masks Temperature Control Temperature Effects Testing Equipment

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• ISSN:
  0892-6298
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  NPPTL - National Personal Protective Technology Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  18-27
• Volume:
  36
• Issue:
  1
• NIOSHTIC Number:
  nn:20059273
• Citation:
  J Int Soc Respir Prot 2019 Oct; 36(1):18-27
• Contact Point Address:
  Samy Rengasamy, National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, Pittsburgh, PA 15236
• Email:
  rda5@cdc.gov
• Federal Fiscal Year:
  2020
• Peer Reviewed:
  True
• Source Full Name:
  Journal of the International Society for Respiratory Protection
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:941e71bdaeb824dbb3e5c46fbe45da6794cf83fd6bf2dcc97a7314fffe90ad31a4548c9345f719042a622f61bead8d73ac5f5e38bf830494153f525dcea2abd0
• Download URL:
  https://stacks.cdc.gov/view/cdc/223551/cdc_223551_DS1.pdf
• File Type:
  [PDF - 202.25 KB ]