Ergonomic comparison of a chem/bio prototype firefighter ensemble and a standard ensemble.

Firefighter turnout gear and equipment protect the wearer against external hazards but, unfortunately, restrict mobility. The aim of this study was to determine the ease of mobility and comfort while wearing a new prototype firefighter ensemble (PE) with additional chemical/biological hazard protection compared to a standard ensemble (SE) by measuring static and dynamic range of motion (ROM), job-related tasks, and comfort. Eight healthy adults (five males, three females), aged 20-40 years, participated in this study. The study consisted of two repeated phases, separated by five uses of the ensembles. Subjects randomly donned either the SE or PE in either dry or wet conditions on separate days. In each phase, five tests were carried out as follows: baseline (non-ensemble), SE-dry, SE-wet, PE-dry, and PE-wet. There was a significant reduction (P < 0.05) of wrist flexion for PE-dry condition compared to the same SE-dry condition. Donning the PE took 80 s longer than the SE in phase 1, this difference disappeared in phase 2. There was a significant decrease (P < 0.05) in post-test comfort wearing the PE compared to the SE. The data collected in this study suggest that, in spite of design features to enhance chemical/biological hazard protection, the PE design does not decrease the wearer's overall functional mobility compared to the SE. However, subjects seem to be more comfortable wearing the SE compared to the PE. These overall findings support the need for a comprehensive ergonomic evaluation of protective clothing systems to ascertain human factors issues.

The impact of protective hoods and their water content on the prevention of head burns in New York City firefighters: laboratory tests and field results.

The New York City Fire Department (FDNY) is the largest fire department in the United States. In 1996, FDNY added the thermal protective hood to its modern protective uniform. The purpose of this study is to determine 1) the effectiveness of hoods in reducing head burns and 2) whether hood water content (dry, damp, or saturated) affects the level of thermal protection. Laboratory tests (radiant heat performance, thermal protective performance, and fully dressed manikin) and FDNY field results were used. Laboratory tests evaluated 4 different conditions (no hood, dry, damp, and saturated hoods) exposed to 4 different heat fluxes (0.1, 0.25, 0.5, and 2.0 cal/cm2/sec) equivalent to approximate air temperatures of 200, 400, 600, and 2,250 degrees F. Field results compared FDNY head burns during 3 winters wearing the hood to 3 winters without hood. Wearing a hood dramatically reduced head burns. This was true for all laboratory tests, at all heat flux exposures, and all hood water content conditions. At 0.1 cal/cm2/sec, dry hoods were superior to wet hoods. At all other heat flux exposures, thermal protection was either not significantly different between water content conditions or improved as water content increased. Confirming these laboratory tests, FDNY field results showed significant decreases in neck burns (by 54%), ear burns (by 60%), and head burn totals (by 46%). Based on combined laboratory and field results, we strongly recommend the use of modern thermal protective hoods.

Selection and testing of a glove combination for use with the U.S. Coast Guard's chemical response suit.

A study was sponsored by the U.S. Coast Guard to select a glove system for its chemical response suit that could meet or exceed the chemical resistance performance of the suit's base material. Three different protective glove combinations were evaluated for their permeation resistance to 28 chemicals. The glove combinations were based on three materials--Viton, butyl rubber, and Silvershield. The test chemicals were selected for one of two reasons. First, no single glove material could be identified to be resistant against the chemical of interest, or second, no permeation test data were available for judging glove material performance for the specific chemical. As can be expected, the permeation resistance of the glove combinations greatly exceeded that of the single glove material components. The butyl rubber/Silvershield glove combination was found to provide permeation resistance greater than 1 hr for all but one of the chemicals tested.

Special considerations for conducting permeation testing of protective clothing materials with gases and chemical vapors.

Testing the permeation resistance of protective clothing materials against chemical gases and vapors requires attention to additional factors over conventional material permeation testing with liquids. Permeation testing factors relevant to gas and vapor challenges are described, and results for testing various material-gas combinations are reported. Challenging protective clothing materials with gases presents a series of special problems including gas delivery, cell integrity, sufficient analytical detection, and disposal. The concentration and other properties of gases and vapors are very sensitive to small changes in temperature and pressure. The method of delivering gases or vapors to the test cell must provide for careful regulation of these variables and maintain homogeneous contact of the chemical with the material over the test period. While many organic vapors are easily and directly detectable by gas chromatographic methods, several gases require special collection media and analytical procedures to achieve detection limits below 1 ppm. Handling of exhaust gas from the challenge chamber of the test cell must reflect safe laboratory practices without creating unnecessary chemical waste. Recommended procedures and results are presented for the six new gases added to ASTM Standard Guide F1001, Selection of Chemical Liquids and Gases to Evaluate Protective Clothing Materials, as well as for other difficult test gases used in evaluating protective clothing materials.