WBGT Clothing Adjustment Factors for Four Clothing Ensembles and the Effects of Metabolic Demands

Details

• Personal Author:
  Ashley CD ; Bernard, Thomas E. ; Caravello V ; Schwartz SW
• Description:
  This study measured the clothing adjustment factors (CAFs) for four clothing ensembles (Cotton Coveralls, Tyvek 1427 Coveralls, NexGen Coveralls, and Tychem QC Coveralls; all coveralls were worn without hoods) against a baseline of cotton work clothes to determine whether the CAFs would be affected by the metabolic rate. Fifteen participants wore one of the five ensembles while walking on a treadmill at low, moderate, and high rates of work in an environment maintained at 50% relative humidity. A climatic chamber was used to slowly increase the level of heat stress by increasing air temperature. When the participant's core temperature reached a steady-state, the dry bulb temperature was increased. The point at which the core temperature began to increase was defined as the inflection point, and the WBGT recorded 5 min before the inflection point was the critical WBGT for each ensemble. A three-way mixed effects linear model with ensemble by metabolic rate category interactions demonstrated that the CAF did not change with metabolic rate, so CAFs can be used over a wide range of metabolic rates. The data at the moderate metabolic rate were combined with data on 14 participants from a previous study under the same conditions. The CAFs in degrees C WBGT were 0 for cotton coveralls, 1.0 for Tyvek 1422A, and 2.5 for NexGen. Although the value of 7.5 for Tychem QC was found, the recommendation remained at 10 to account for the effects of humidity. The standard error for the determination of WBGT crit at 50% relative humidity was 1.60 degrees C WBGT. [Description provided by NIOSH]
• Subjects:
  Environment Heat Stress Disorders Hot Temperature Humidity Occupational Health Personal Protective Equipment Protective Clothing Safety Temperature
• Keywords:
  Air Temperature Author Keywords: Heat Stress Body Temperature Clothing Environmental Factors Heat Heat Exposure Heat Stress Metabolic Rate Physiological Testing Protective Clothing Statistical Analysis Temperature Control Temperature Effects Threshold Limit Values TLV

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Florida ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-5
• Volume:
  5
• Issue:
  1
• NIOSHTIC Number:
  nn:20033460
• Citation:
  J Occup Environ Hyg 2008 Jan; 5(1):1-5
• Contact Point Address:
  Thomas E. Bernard, University of South Florida, College of Public Health, 13201 Bruce B. Downs Blvd., Tampa, FL 33612-3805
• Email:
  tbernard@health.usf.edu
• Federal Fiscal Year:
  2008
• NORA Priority Area:
  Research Tools and Approaches: Exposure Assessment Methods
• Performing Organization:
  University of South Florida, Tampa, Florida
• Peer Reviewed:
  True
• Start Date:
  20000930
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20040929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c9447312064ff0afc88c2d27ec05cc3580027537b18a729bc578f1666f58fd078b8e48843c62924534d5403dcd4ccaa084c76a0d99e755428148ad8d3c58f4d5
• Download URL:
  https://stacks.cdc.gov/view/cdc/189034/cdc_189034_DS1.pdf
• File Type:
  [PDF - 286.85 KB ]