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Carbon monoxide poisonings from small, gasoline-powered, internal combustion engines: just what is a "well-ventilated area?"

Earnest G; Mickelsen R; O'Brien D; McCammon J
American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas. Fairfax, VA: American Industrial Hygiene Association, 1997 May; :31
Many workers are poisoned each year in buildings or semienclosed spaces by carbon monoxide (CO) produced by small, gasoline-powered engines used on tools, such as high pressure washers, concrete cutting saws, compressors, and generators. These products are typically sold with an ambiguous warning stating that they should only be used in "well ventilated areas." Workers have been poisoned by CO because they did not recognize the danger or understand the warning. The authors modeled the time required for a gasoline-powered, 5-horsepower (hp), 4- cycle engine to generate CO concentrations exceeding the National Institute for Occupational Safety and Health (NIOSH) recommended 200-ppm ceiling and 1200 ppm immediately dangerous to life and health concentrations for various room sizes and the general ventilation rates. The model was compared to field data collected at a site where two workers had previously been poisoned while operating a 5-hp concrete saw in a bathroom having open doors and an operating ventilation system. The model and field data indicate that hazardous CO concentrations can develop within minutes. The model indicates that ventilation rates of nearly 5000 cfm (120 air changes per hour) would have been required to prevent the CO concentration from exceeding the 200-ppm ceiling. Workers need to understand the CO poisoning hazard and should be provided with adequate warning form the manufacturer. Opened windows or doors or an operating fan does not provide sufficient ventilation. These poisonings can occur quickly, even in the presence of what many would consider a well-ventilated area. To prevent CO poisoning from small gasoline-powered engines, the engines should not be operated inside of buildings or in semienclosed spaces. Manufacturers of tools that generate carbon monoxide and could be used in buildings or semienclosed spaces should improve their warnings and begin to develop engineering control options to better protect the users.
Workers; Work-areas; Gases; Poison-gases; Poisons; Ventilation; Air-contamination; Air-quality; Hazards; Environmental-hazards; Environmental-exposure; Exposure-levels
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American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas
Page last reviewed: March 25, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division