NIOSHTIC-2 Publications Search

Follow up evaluation of Kohler low emission technology to prevent carbon monoxide poisonings from houseboat generator exhaust.

Garcia A; Dunn KH; Sestito N
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 289-14, 2011 Jul; :1-25
In recent years, researchers from the National Institute for Occupational Safety and Health (NIOSH), working under an interagency agreement with the United States Coast Guard, evaluated carbon monoxide (CO) emissions and exposures from gasoline-powered generators equipped with emission control devices. This evaluation was part of a series of studies conducted by NIOSH investigators to identify and recommend effective engineering controls to reduce the CO hazard and prevent CO poisonings on houseboats and other recreational marine vessels. In previous studies, NIOSH researchers have evaluated CO emissions from Westerbeke generators that have included the necessary technology to reduce and control CO emissions. Kohler Power Systems recently released to the public a new line of low CO emission generators with catalytic technology. During this study, NIOSH engineers conducted a follow up evaluation of a 15 kW low CO emission Kohler generator installed in a 16' x 59' houseboat equipped with a stack exhaust configuration. At the time of this evaluation, the 15 kW generator was the largest low CO generator manufactured by Kohler for the houseboat market. The new Kohler generator had been used for a full rental season and it recorded 1082 hours prior to the evaluation. Representatives from Kohler, the U.S. Coast Guard, and Forever Resorts attended the evaluation. Results from this follow up evaluation on the Kohler 15 kW low CO emission generator showed higher levels of CO when compared to results obtained from the initial evaluation. Average onboard environmental CO concentrations measured at various locations on the houseboat were generally single digit concentrations. Inspection of the catalytic converter element showed complete degradation of the ceramic element that composes the catalytic converter. The catalytic converter was replaced and CO concentrations were again consistent with the results obtained from the initial evaluation. Following the cold start of the engine, initial CO concentrations reached approximately 80,000 ppm and then decreased to 3500 - 5000 ppm within 3 - 5 minutes after cold start. Once the catalytic converter was replaced, these CO concentrations decreased to 200 - 300 ppm within 4 to 5 minutes after initial start up. The combination of well maintained low-emission technology along with a well designed stack led to low environmental CO concentrations at all measured locations on the houseboat (usually single digit concentrations). It is important that the boater/owner/operator follow all maintenance recommendations provided by the manufacturer. For the Kohler low emission generator, some of those recommendations include checking/replacing the catalyst every 500 hours or yearly. Use of the vertical exhaust stack with low emission generators is recommended, as this will ensure redundancy in the system in the event of catalyst degradation or oxygen sensor malfunction. Development and commercialization of these systems is a major step forward in control systems to provide a safer environment around houseboats and other marine vessels.
Control-technology; Control-systems; Controlled-atmospheres; Emission-sources; Poison-control; Poison-gases; Region-9; Boat-manufacturing-industry; Petroleum-products; Fuels; Fumes; Engineering-controls; Marine-workers; Equipment-design; Equipment-reliability; Exposure-assessment; Exposure-levels; Catalysis; Ceramic-materials; Environmental-control-equipment; Environmental-exposure; Environmental-hazards; Environmental-protection; Hazardous-materials; Motor-vehicle-parts; Exhaust-gases; Exhaust-systems; Exhaust-ventilation; Outdoors; Oxides; Author Keywords: Carbon Monoxide; Houseboats; Marine Generators
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
Transportation, Warehousing and Utilities; Manufacturing
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