CDC logoSafer Healthier People CDC HomeCDC SearchCDC Health Topics A-Z
NIOSH - National Institute for Occupational Safety and Health

Skip navigation links Search NIOSH  |  NIOSH Home  |  NIOSH Topics  |  Site Index  |  Databases and Information Resources  |  NIOSH Products  |  Contact Us



  • During a pandemic influenza, healthcare workers (HCW) will be utilizing respirators for protracted periods of time (8-12 hr shifts) that could lead to CO2 retention, decreases in O2 saturation, and performance decrements. This study will evaluate transcutaneous CO2 levels and O2 saturation associated with respirator use at workrates typical for HCW
Healthcare workers wearing respirators / Oxygen sensor on ear lobe

Applicable Standards

  • OSHA standard (29 CFR 1910.134) is 19.5% O2 concentration to altitude of 8,000 feet
  • No current standard exists for CO2 levels in filtering facepiece respirators or elastomeric respirator
  • Will apply to ISO/TC94/SC15/WG1/PG5 Human Factors O2/CO2 Guidance document currently being developed (N105)

Key Partners

  • Veterans Administration


  • Healthcare workers (medical, dental, veterinary)
  • Emergency Medical Services (paramedics, firefighters, private ambulance crews)
  • Industrial workers
  • Respirator manufacturers

Project Scope

  • Conduct human physiologic testing in the NPPTL physiology lab
  • Determine CO2 and O2 concentrations in respirator deadspace and simultaneous transcutaneous CO2 levels and O2 saturation while wearing N95FFR, elastomeric , and N95FFR with surgical mask overlay
  • Correlate respirator deadspace CO2 and O2 concentrations with transcutaneous CO2 levels and O2 saturation
  • Incorporate data from the project into the development of physiologic guidelines for respirator use


  • Q1 write protocol
  • Q2 obtain peer review, HSRB approval
  • Q3 procure equipment, recruit subjects
  • Q4 begin data collection


  • Manuscripts submitted to peer-reviewed journals
  • Presentations at national/international conferences
  • Development of new NIOSH guideline for CO2 tolerance levels when using filtering facepiece respirators and elastomeric respirators


  • Introduction of physiologic variables (CO2 levels, O2 saturation) into NIOSH respirator selection logic
  • Appropriate mitigation strategies for elevated CO2 and decreased O2 associated with FFR use incorporated into CDC, NIOSH, WHO, and ISO guidance documents
  • Effects on respiratory gases of combined N95FFR/surgical mask overlay, used to support/modify CDC, NIOSH, WHO, ISO, etc. standards and guidance documents
Page last updated: August 08, 2008
Page last reviewed: August 08, 2008
Content Source: National Institute for Occupational Safety and Health (NIOSH)