Thermal Capacity of Fire Fighter Protective Clothing

Details

• Corporate Authors:
  National Institute for Occupational Safety and Health ; National Institute of Standards and Technology ; North Carolina State University
• Description:
  A laboratory testing procedure has been demonstrated for measuring the transmitted and stored thermal energy in moisture preconditioned turnout systems exposed to sub-flashover level radiant heat (0.2 cal/cm2sec). Figure 1 shows the range of performance for twenty-eight different turnout materials configurations tested using this stored energy test (SET) method. Differences in thermal liners or outer shell fabrics have less pronounced effect compared to differences in moisture barrier permeability and trim porosity. This laboratory based study shows that the Stored Energy Test (SET) method provides information not provided by any other protective performance test method currently incorporated in NFPA 1971 Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting. It supports a hypothesis that sub-flashover burn injuries may occur as the result of two different heat transmission mechanisms, or combination of two thermal phenomena. Tests conducted on moisture preconditioned materials exposed for 1.5 and 2.0 minutes to 0.2 cal/cm2sec radiant heat, predict burns mainly from transmitted thermal energy. For these conditions, the SET functions essentially as a Radiant Protective Performance (RPP) test for moist samples with attached trim or reinforcements. For 1.0 minute radiant heat exposure followed by contact compression, SET performance is more noticeably influenced by thermal energy discharged from the heated turnout materials. Both phenomena could contribute to the burn hazard, depending on the specifics of the heat exposure and other conditions of use. In both scenarios, the presence of non porous reflective trim or non porous reinforcements reduces test performance when these materials are attached to the outer surface of a turnout composites consisting of a thermal liner, outer shell and a breathable moisture barrier. Technical information has been provided that should be useful to the NFPA 1971 committee currently considering the establishment of performance criteria based on the results of this test method. By helping to identify material factors associated with SET performance, this study also provides insights into how turnouts may be designed to improve thermal protection in subflashover thermal exposures. In this regard, this research was limited to investigating a relatively small group of turnout materials and features used in turnout constructions. There is a need for tests on a wider range of configurations, including constructions that could mitigate SET degrading effects in breathable turnouts. More tests are needed to more fully qualify all the observed materials effects, and to better understand these complex interactions. There is particular need for more tests at the 60 seconds thermal exposure condition. This study indicates that the same turnout materials properties associated with higher levels of total heat loss (THL) can degrade performance in the SET. It would be useful, therefore, to generate THL data on turnout samples also tested in the SET. Data on thermal protective performance (TPP) would also be of value in demonstrating how the SET differentiates from this established test method. [Description provided by NIOSH]
• Subjects:
  Fires Hot Temperature Occupational Health Personal Protective Equipment Protective Clothing Safety
• Keywords:
  Fire Fighting Equipment Fire Resistant Materials Heat Exposure Personal Protective Equipment PPE Protective Clothing Thermal Properties
• Publisher:
  The Fire Protection Research Foundation
• Document Type:
  Text
• Genre:
  Report
• Place as Subject:
  Maryland ; Massachusetts ; North Carolina ; OSHA Region 1 ; OSHA Region 3 ; OSHA Region 4 ; 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:
  1-33
• NIOSHTIC Number:
  nn:20057319
• Citation:
  Quincy, MA: The Fire Protection Research Foundation, 2008 Oct; :1-33
• Contact Point Address:
  The Fire Protection Research Foundation, One Batterymarch Park, Quincy, MA, USA 02169-7471
• Email:
  foundation@nfpa.org
• Federal Fiscal Year:
  2009
• Peer Reviewed:
  False
• Source Full Name:
  Thermal capacity of fire fighter protective clothing
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:89a573a51a5f64aa3aa360b968e2d5628a620bd0052778a9bbb1e1fdceaa11620150177eca60ba1ede0589bfda9daa0ef41725ccd6a631b1c46cff9f8f0f56d9
• Download URL:
  https://stacks.cdc.gov/view/cdc/214708/cdc_214708_DS1.pdf
• File Type:
  [PDF - 939.46 KB ]