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An evaluation of issues related to the performance of exhaust stacks to prevent carbon monoxide poisonings on houseboats.

Hammond D; Earnest G; Hall R
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :42-43
National Institute for Occupational Safety and Health (NIOSH) researchers evaluated the performance of exhaust stacks retrofitted onto houseboat generators at Lake Cumberland, Kentucky. The exhaust stack is a new technology that NIOSH has repeatedly evaluated in recent years. Those evaluations showed that the exhaust stack reduced carbon monoxide (CO) exposures by up to 99%. The Houseboat Industry Association requested that NIOSH evaluate exhaust stack performance under high temperatures and humidities, high generator loads, extra boat weight, and at night in a cove. Most houseboat manufacturers currently use side exhausted generators. Three exhaust configurations were evaluated: side-exhaust, vertical stack, and flagpole stack. Ambient test conditions ranged from 18-31 degrees C with relative humidities of 32-95%. Study results showed that stacks were safer than side exhaust under all conditions tested. During the side exhaust evaluation, CO concentrations on the swim platform exceeded 1000 ppm and average concentrations were approximately 341 ppm. Evaluation of the vertical exhaust stack for all conditions had average CO concentrations on the swim platform generally below 5 ppm and peaks below 50 ppm. Evaluation of the flagpole stack was similar with peak CO concentrations below 20 ppm and average concentrations below 2 ppm. CO concentrations measured on the upper decks were lower for stack than side exhaust [peak of 178 ppm (vertical stack)/ 94 ppm (flagpole stack) vs. 929 ppm (side)]. Although the exhaust stacks generally performed well, NIOSH engineers recommend that modifications to reduce static pressure in the stack be made to improve performance. Peak concentrations on the upper deck could be further reduced by extending the stack. This study showed that houseboats having gasoline-powered generators with properly designed exhaust stacks will reduce CO exposures and poisonings.
Exhaust-systems; Exposure-levels; Exhaust-gases; Engineering-controls; Control-technology; Poison-gases
Publication Date
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NIOSH Division
Priority Area
Research Tools and Approaches: Control Technology and Personal Protective Equipment
Source Name
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division