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An evaluation of catalytic emission controls and vertical exhaust stacks to prevent carbon monoxide poisonings from houseboat generator exhaust.

Zimmer AT; Earnest GS; Kurimo R
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, EPHB 171-36a, 2005 Sep; :1-28
Working under an interagency agreement with the United States Coast Guard, researchers from the National Institute for Occupational Safety and Health (NIOSH) evaluated carbon monoxide (CO) emissions, exposures, and controls from gasoline-powered generators on houseboats. This evaluation is part of a series of studies conducted by NIOSH investigators during the past several years to identify and recommend effective engineering controls to reduce the CO hazard and eliminate CO poisonings on houseboats and other recreational marine vessels. The performance of two (14 KW and 20 KW) Westerbeke, Safe-CO Generators were tested. Using electronic fuel injection and a catalytic air pollution control device, these generators were specifically designed to reduce carbon monoxide emissions to protect the boating occupants. To prevent excessive heat buildup in the catalyst, the device was also water jacketed. This represented an improvement over previously tested engineering control devices by reducing their fire hazard potential (Earnest, Dunn et al. 2003). The houseboat containing the 14 KW generator had been modified so that testing could be accomplished using either a side exhaust or top exhaust configuration. At the request of Fun Country Marine, a 12.5 KW Westerbeke generator was also tested that had been retrofitted with a Zenith Electronic Fuel Injection Kit (EFI). When comparing the real-time results for the side versus top stack exhaust, slightly higher concentrations were noted on the lower stern deck in the side exhaust configuration. Although the use of the low Safe-CO generator resulted in low CO concentrations for either configuration, the use of the vertical exhaust is recommended as a prudent control technology. For example, not changing the catalyst would result in performance degradation over time resulting in higher than expected emissions. The use of a vertical stack would insure that exhaust emissions were located well away from boaters to reduce their potential for exposure. The performance of the Westerbeke Safe-CO generators was impressive with stack CO emission of approximately 200 ppm for the fully warmed generator. Due to diffusion, these emissions were significantly reduced such that highest average real-time CO reading, obtained from the monitors placed throughout the houseboat, was 9.3 ppm (side exhaust configuration). In addition, the performance of the Westerbeke generator retrofitted with a Zenith EFI was excellent with a stack CO emission below 1,000 ppm for the fully warmed generator. Given the low hours of operation for all of the generators tested, it is important to conduct addition tests at the end of the houseboat season to determine if there are any performance degradations.
Region-9; Control-technology; Environmental-control-equipment; Environmental-exposure; Exhaust-gases; Exhaust-ventilation; Boat-manufacturing-industry; Poison-control; Poison-gases; Engineering-controls; Equipment-design; Emission-sources; Combustion-gases
National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Mail Stop R-5, 4676 Columbia Parkway, Cincinnati, OH 45226
Publication Date
Document Type
Field Studies; Control Technology
Funding Type
Interagency Agreement
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
NIOSH Division
Priority Area
Research Tools and Approaches: Control Technology and Personal Protective Equipment
Source Name
National Institute for Occupational Safety and Health
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division