The Role of the Moisture/Vapour Barrier in the Retention of Metabolic Heat during Fire Fighting
Abstract
The relationship between metabolic heat build-up and the vapour permeability of the barrier layer in fire turnout clothing was examined under a variety of conditions. Laboratory exercise tasks were used to simulate the work of fire fighters performing under three different environmental conditions, cold, hot and extended very hot conditions. The laboratory studies were followed by a field trial in which true fire fighting activities were performed. The clothing elements examined included three outer shells, five moisture/vapour barrier configurations, and two thermal liners. Ten parameters indicative of thermal physiological strain were monitored in eight professional fire fighters to assess the role of the barrier in the retention of metabolic heat. The results showed that the moisture/vapour barrier material/configuration was the dominant factor in determining thermal physiological strain, with the shell and liner playing very minor roles. Differences in strain as a function of barrier were discernible even under low to moderate stress, but became more pronounced with higher ambient temperatures and longer work periods. The laboratory results were clearly substantiated during the field trial It is concluded that a full vapour barrier of a material such as neoprene leads to significantly higher thermal physiological strain than a vapour permeable water barrier of a material such as GORE-TEX. Partial coverage barriers of either material provide even greater reduction in strain, and omission of the barrier entirely is best from a physiological perspective.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1988
- Accession Number
- ADA204304
Entities
People
- John Frim
- Tiit T. Romet
Organizations
- Defence Research and Development Canada