Physiological and thermoregulatory responses to wearing N95 filtering facepiece respirators

Details

• Personal Author:
  Benson SM ; Kim J-H ; Roberge RJ
• Description:
  The use of filtering facepiece respirators (FFR) has increased enormously in both public and occupational sectors for respiratory protection from infectious airborne particles. The N95 class of FFR, which filters out at least 95% of airborne particles >0.3 um, is the most common type of FFR; however, there has been a lack of scientific information on physiological and thermal burdens of wearing N95 FFR. PURPOSE: To investigate physiological and thermoregulatory responses to wearing N95 FFRs while performing low-moderate intensity exercise. METHODS: Twenty healthy subjects (13 men, 7 women), who passed a physical examination and a respirator quantitative fit test, performed three trials of treadmill exercise (5.6 km/h, 0% grade, 60min duration) in a thermoneutral environment (21.4+/-0.7 degrees C, 23.5+/-7.9%) while wearing two popular styles (cup-shaped and flat fold) of N95 FFR or not wearing FFR for control (CON). Study variables included core body temperature (Tco), skin temperature at the cheek (Tcheek) and abdomen (Tabdomen), heart rate (HR), respiratory rate (RR), transcutaneous carbon dioxide (tcPCO2), and oxygen saturation (SpO2). Deadspace microclimate temperature and humidity were also measured in FFR trials. Data were analyzed by two-way (Trials x Time) repeated measures ANOVA. RESULTS: Tco, Tcheek, and Tabdomen rose significantly by time in all trials (p<0.001) and the final deadspace microclimate temperature and humidity reached up to 33 degrees C and 90%, respectively. However, there was no statistical difference in these temperature variables between CON and the FFR trials. HR and RR increased significantly by time in all trials (p<0.001), but at a greater rate in the FFR trials than in CON (HR; P<0.001, RR; P<0.01). There was no statistical difference in SpO2 levels between CON and FFR trials, however, tcPCO2 levels were significantly higher in the FFR trials than in CON (p<0.001). CONCLUSION: Wearing N95 FFR while performing low-moderate work for 60 min in a thermoneutral environment did not impose a significant thermal burden on the wearer. However, significantly elevated HR and RR in the FFR trials indicated that wearing N95 FFR may add additional metabolic demands. Also, breathing through N95 FFR did not interfere with SpO2, but caused some mild degree of CO2 retention (tcPCO2 >/= 45 mmHg). [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Dust Occupational Health Particulate Matter Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety Temperature
• Keywords:
  Airborne-dusts Airborne-particles Filters Particulate-dust Particulates Physical-exercise Physiological-effects Physiological-factors Physiological-function Respirators Respiratory-equipment Respiratory-protection Respiratory-protective-equipment Statistical-analysis Temperature-effects Temperature-measurement Thermal-effects

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• ISSN:
  0195-9131
• Document Type:
  Text
• Genre:
  Abstract or Summary
• 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
• Volume:
  44
• NIOSHTIC Number:
  nn:20041974
• Citation:
  Med Sci Sports Exerc 2012 May; 44(5S)(Suppl 2):319
• Federal Fiscal Year:
  2012
• NORA Priority Area:
  Healthcare and Social Assistance
• Peer Reviewed:
  False
• Source Full Name:
  Medicine and Science in Sports and Exercise
• Supplement:
  2
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ccc540d77546fc1ff88c2a8c6c367f245925fe5c037ce4311e2bb019a9a28e3635b568619a2ed9c1cb21f59a0b783fb533d9d7f3978d93505853256cb117111c
• Download URL:
  https://stacks.cdc.gov/view/cdc/194362/cdc_194362_DS1.pdf
• File Type:
  [PDF - 82.03 KB ]