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Carbon Monoxide Intoxication Associated with Use of a Gasoline-Powered Resurfacing Machine at an Ice-Skating Rink -- Pennsylvania

On December 3, 1983, the Chester County (Pennsylvania) Health Department (CCHD) received a report that 15 persons had become acutely ill while participating in an ice-hockey game. The game was held on an enclosed rink housed in a local sports arena. Thirteen of the victims were teenaged players, and two were coaches. All but one were associated with the same team. One referee also complained of a severe headache but failed to recognize the significance of the symptom and did not halt the game.

Symptoms included: nausea, lethargy, and headache (12 team members); vomiting (five); unconsciousness (one). All were removed from the premises to provide fresh air and then transported to an area hospital. Oxygen was given enroute and in the hospital emergency room. A carboxyhemoglobin level taken nearly 2 hours after acute onset on the individual most affected was 9.8%. Extrapolating back (at the rate of 50% decrease in concentration per half hour of oxygen therapy) (1), carboxyhemoglobin levels were estimated at 35% or more at the time of his loss of consciousness. Fourteen victims were subsequently released; the one who had suffered unconsciousness was admitted for observation. The clinical diagnosis was suspected carbon monoxide (CO) intoxication. Telephone contact with CDC confirmed CO as a known hazard for such rinks (2).

Questioning of the coaches and families revealed no other common factors, and there was no evidence of food poisoning. Inspection of the skating rink's environmental conditions provided evidence for potential CO intoxication. The ice resurfacing machine, originally designed to be powered by propane, had been converted to a gasoline-driven engine. Sampling by CCHD environmental staff, using a Bendix Gastec* pump and CO analyzer tube, showed elevated levels of CO (up to 100 parts per million (ppm)) both immediately and 2-3 hours after running the resurfacing machine for 10 minutes. The CO concentration did not decrease appreciably after 2 hours; this was considered highly significant, because the machine is usually run from four to 11 times per day, and the enclosed arena had no specific exhaust system to provide for total air exchange. No other source of CO was found.

Following a cease-and-desist order issued by the CCHD, the resurfacing machine was taken out of service and successfully reconverted to a propane-power source. However, the initial propane reconversion also produced excessive levels of CO production, because the fuel mixture was "too rich." Following proper adjustment and tuning of the engine, subsequent indoor CO levels remained at an average 5-10 ppm, even after multiple uses of the machine up to 10 times per day. No additional illnesses have been reported.

The ability of CO to combine competitively with hemoglobin and the very strenuous level of metabolic activity involved in competitive, high-school-level hockey, would explain acute CO intoxication in such cases, particularly after multiple uses of the resurfacing machine in an inadequately ventilated enclosed arena. Reported by HL Russell, VMD, JA Worth, WP Leuchak, P Terry, S Pollock, DA Turney, DA Jackson, JP Maher, MD, Chester County Health Department, Pennsylvania; Investigations Section, Special Studies Br, Chronic Diseases Div, Center for Environmental Health, CDC.

Editorial Note

Editorial Note: Each year in the United States, an estimated 10,000 persons seek medical attention or lose at least 1 day of normal activity because of CO intoxication; at least 1,500 persons die from accidental exposure to high concentrations of CO. In addition to acute lethal CO poisoning, considerable hazard occurs from frequent exposure to low concentrations of CO in homes, work places, schools, and recreational buildings. Prolonged exposure to low levels of CO causes nausea, vomiting, and heart palpitations.

Numerous studies have demonstrated the seriousness of the CO problem. One study, in particular, further illustrates a potential problem in ice-skating rinks where gasoline-powered equipment is used in confined areas. A 1978 Harvard School of Public Health study found the national air quality standard adopted for outdoor exposure to CO** was exceeded in over 80% of the sampled hours in ice-skating rinks located in the Boston area. The use of gasoline-powered ice-resurfacing machines and the improper or inadequate venting of exhaust emissions caused this excessive level of CO.

Although exhaust from any improperly maintained vehicle can pose serious health hazards, the most common source of CO is automobile exhaust or exhaust vented into confined spaces. Because gasoline-powered lawnmowers, charcoal grills, wood stoves, fireplaces, gas space heaters, kerosene or gas-powered camp lanterns, heaters, stoves, and similar equipment also produce CO, proper ventilation and prevention of CO build-up must be assured to protect human health in areas where this equipment is operated.

The following guidelines summarize the most important techniques for preventing CO intoxication: (1) Provide adequate ventilation in areas where a known source of CO exists indoors. Ensure that all fuel-burning appliances or equipment are appropriately used indoors (i.e., never burn charcoal indoors), and are properly installed, adjusted, and operated; (2) do not operate gasoline-powered engines in confined spaces; (3) have a qualified technician install or convert fuel-burning equipment from one type of fuel to another, taking into consideration the ability of the ventilation system to handle additional indoor air pollution.


  1. Kaye S. Handbook of emergency toxicology: a guide for the identification, diagnosis, and treatment of poisoning. 3d ed. Springfield, Illinois: CC Thomas, 1970:194.

  2. Davis BP, Drenchen A. Carbon monoxide and concern in ice arenas. J Environ Health. 1979:42;120-2.

  3. CDC. Carbon monoxide intoxication--a preventable environmental health hazard. MMWR 1982;31:529-31. *Use of trade names is for identification only and does not imply endorsement by the Public Health Service or the U.S. Department of Health and Human Services. **The Environmental Protection Agency ambient air quality standard for CO is 9 ppm-maximum 8-hour concentration not to be exceeded more than once per year and 35 ppm-maximum 1-hour concentration not to be exceeded more than once per year. The National Institute for Occupational Safety and Health recommends that the occupational standard for CO be 35 ppm as a time-weighted average (TWA) exposure for an 8-hour workday and 200 ppm as a maximum concentration. The Occupational Safety and Health Administration's standard is 50 ppm as an 8-hour TWA.

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