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Comparison of laboratory-measured plasma and salivary
osmolality with salivary osmolality determined by a hand-held osmometer in acute 3%-5% dehydration status– FY09

NOTE: This page is archived for historical purposes and is no longer being maintained or updated.


  • The objective of this study is:

    • To determine the accuracy of salivary osmolality measurements taken with a new hand-held osmometer compared to a standard laboratory osmometer using freeze point depression technology during states of acute, mild dehydration (3%, 5%),
    • To evaluate any correlation between salivary osmolality by both pieces of equipment with plasma osmolality measured by the standard laboratory osmometer
    • To examine the effect of various subject characteristics (i.e., age, gender, fitness, smoking) upon readings from the hand-held salivary osmometer.

Applicable Standards

  • ASTM F 2668-07 Standard Practice for Determining the Physiological Responses of the Wearer to Protective Clothing Ensembles
  • ISO 7933 Hot Environments – Analytical Determination and Interpretation of Thermal Stress Using Calculation of Required Sweat Rates

Key Partners

  • Technical Support Working Group (Washington, DC)
  • Cantimer, Inc. (Menlo Park, CA)
  • Woolongong University (Australia)


  • Firefighters
  • Military Personnel
  • Agricultural workers
  • Roofers
  • Lifeguards

Project Scope

  • This study may require ~60 subjects to complete all phases. If the hand-held osmometer is found to be accurate, this could allow for detection of early dehydration in populations at risk (e.g., firefighters, military personnel, roofers, agricultural workers, etc.).


  • Q1 Send draft protocol to TSWG for approval (completed, December, 2008) and Send draft dehydration protocol out for peer-review (completed, January 2009)
  • Q2 Submit draft protocol to HSRB for approval and Obtain HSRB approval and begin subject recruitment (Spring, 2009)
  • Q3 Recruit an initial 30 subjects, complete first phase (medical screening, GXT) and second phase (dehydration induction and laboratory measurements) of dehydration study (Fall of 2010)
  • Q4 Complete third phase of dehydration study (dental appliance use, SCBA use)


  • Final Report to the client (TSWG)
  • Publications in peer-reviewed journals
  • Guidance documents to key stakeholders on thermal stress monitoring


  • Use of data in the development and modification of standards (ASTM, ISO) related to heat stress and hydration status.
Page last updated: April 05, 2010
Page last reviewed: April 14, 2009
Content Source: National Institute for Occupational Safety and Health (NIOSH)
National Personal Protective Technology Laboratory