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An evaluation of an engineering control to prevent carbon monoxide poisonings of individuals on houseboats at Sumerset Custom Houseboats, Somerset, Kentucky.

Dunn KH; Hall RM; McCammon JB; Earnest GS
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 171-26a, 2001 May; :1-29
During the period of 1990 to 2000, 111 carbon monoxide (CO) poisoning cases occurred on Lake Powell near the border of Arizona and Utah. Seventy-four of the poisonings occurred on houseboats, and sixty-four of the poisonings were attributable to generator exhaust alone. Nine of the 111 CO poisonings resulted in death. The National Institute for Occupational Safety and Health (NIOSH) conducted an evaluation of an engineering control installed on a houseboat generator to reduce the hazard of CO poisonings from the generator exhaust. The control consisted of a water separator and an exhaust stack outfitted onto a gasoline-powered generator that extended to just below the upper deck on the port side of the houseboat. An extension to the exhaust stack which raised the outlet to 7 feet above the top deck was retrofitted and also tested. When comparing the results of the current evaluation to previous studies, the use of an exhaust. stack provides dramatically lower exposure to hazardous levels of CO to individuals on or near the houseboat. The CO concentrations on the swim platform were reduced by ten times or more when compared to boats which exhaust out of the transom underneath the swim platform. The current study found that the extension of the exhaust stack well above the upper deck further reduced CO concentrations at all locations on both the lower and upper decks. CO concentrations on the swim platform of the houseboat, an area where occupants frequently congregate, were an average of 6.05 ppm at the short stack height (exhaust stack terminating just below the upper deck) and were reduced to 0.84 ppm with the tall stack configuration (exhaust stack terminating 7 feet above the upper deck). CO concentrations were also reduced on the upper deck of the houseboat. The primary benefit of extending the exhaust stack is that the peak concentrations were reduced in all locations, in most cases by ten times or more. The peak concentration at one location on the top deck was reduced from 459 ppm to 4 ppm. Based upon the results of this and other studies, it appears that retrofitting houseboats, using gasoline powered engines, with an exhaust stack that extends well above the upper deck will greatly reduce the risk of CO poisoning and possible death to individuals on or near the houseboat.
Exhaust-gases; Exhaust-systems; Toxic-gases; Poison-gases; Region-4; Engineering-controls; Electrical-generators; Combustion-gases; Combustion-engines; Combustion-products; Accident-prevention; Injury-prevention; Acute-toxicity
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Field Studies; Control Technology
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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