Small Engines Produce Hazardous Levels of Carbon Monoxide: Farmers are Poisoned while Cleaning Animal Housing

  • Ehlers, Janet;
  • Booher, Donald E.;
  • Chapman, R.;
  • Kahle, M.;
  • Kuhse, W.;
  • Roberts, D.;
  • Venable, Herbert L.;
  • Wallingford, Kenneth M.

Five farmers were poisoned with carbon monoxide (CO) when using gasoline-powered pressure-washers inside animal buildings on Iowa farms between January, 1992 and January, 1993. Three victims were overcome after only 1/2 hour of washer operation. A 35-year-old man died and a 12-year-old boy was hospitalized for hyperbaric oxygen treatment. Carboxyhemoglobin levels were elevated in all cases where blood levels were available. Since the original investigation, additional cases of CO poisoning related to pressure washers have been reported to the OHNAC project. Of the total of 18 cases, 12 occurred while cleaning swine buildings, 2 in dairy operations, and 4 during flood clean-up. In each of the incidents identified, victims had brought the four to thirteen horsepower machines indoors. Poisonings occurred in several cases even though doors and windows were left open. Most of the victims were unaware that there was a significant risk of CO poisoning when using pressure washers. In field investigations, the National Institute for Occupational Safety and Health (NIOSH) measured the generation of CO by a GPP washer under environmental conditions comparable to those experienced by the cases in this report.

CO can build up rapidly and overcome workers without warning symptoms. When not fatal, CO poisoning can cause permanent brain damage. The number of swine farmers using pressure washers is probably increasing.

Based on our investigation, we concluded that, in many work environments, including agriculture, there may be no practical means to determine whether ventilation is adequate for safe operation of small engines indoors. Therefore, even brief indoor use of GPP washers is hazardous (CDC, October 15, 1993). When used to clean buildings, gasoline-powered machines should be placed outside and only the hoses brought inside. Furthermore, we concluded that information about the hazard needs to be disseminated to anyone concerned with the manufacture, distribution, and operation of this type of equipment.

This problem was identified through Occupational Health Nurses in Agricultural Communities (OHNAC), a national surveillance program conducted by NIOSH that has placed public health nurses in rural communities and hospitals in 10 states to conduct surveillance of agriculture-related illnesses and injuries that occur among farmers and their family members. OHNAC surveillance data are used to assist in the reduction of occupational illness and injury in agricultural populations.

This research abstract was extracted from a portion of the proceedings of "Agricultural Safety and Health: Detection, Prevention and Intervention," a conference presented by the Ohio State University and the Ohio Department of Health, sponsored by the Centers for Disease Control/National Institute for Occupational Safety and Health.

J. Ehlers, H. Venable, K. Wallingford, D. Roberts, D. Booher, NIOSH, Cincinnati, OH; R. Chapman, M. Kahle, W. Kuhse, Iowa Dept. of Public Health, Des Moines, IA.

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