Case Histories of Carbon Dioxide Incidents

There have been specific cases where carbon dioxide has caused fatalities. The objective of these citations would be to demonstrate that while CO2 might not be considered a hazardous substance under typical existing federal regulations (ex: CERCLA or RCRA), certain conditions may elevate concentrations which may be considered toxic, and/or displace oxygen to hazardous levels. The specific OSHA and the Mammoth Mountain USGS cases do not have direct links (as existed in the past) but can be reached by going to the Occupational Safety & Health Administration website and using the "search" for carbon dioxide.


The first case was the fatality in Britain's former coalfields near Northumberland. An unusual weather condition created a pressure drop which vented accumulated carbon dioxide from an abandoned mine working which overcome a 60-year old male walking in the area. The dangers of carbon dioxide (stythe), is presented in the attached news releases from the British Geological Survey and other sources.


The second case was the fatality of a refrigeration repairman in Boston. The repairman was overcome by dangerous levels of carbon dioxide from the evaporation of blocks of dry ice. The carbon dioxide released from the dry ice accumulated in a walk in freezer in a restaurant. This citation was from an OSHA Region I News Release. The various citations and proposed penalties against the restaurant included failure to provide the place of employment free from recognized hazards, citing an immediately dangerous to life and health (IDLH) carbon dioxide concentration of 40,000 parts per million.


The third case represents the carbon dioxide study at Mammoth Mountain, California. This study is on the release of magmatic carbon dioxide. The carbon dioxide originates at depth and migrates to the surface and in the soil void space. The accumulation of carbon dioxide in the soil void space was not recognized until 1994. This U.S. Geological Survey (USGS) study has documented that carbon dioxide exceeding OSHA standards have been measured in test pits in soil, snow, and in poorly ventilated buildings. The samples of soil gas showed a range of less than 1 per-cent (background) to greater than 95 per-cent by volume. The chemical analysis has shown that the soil gas in anomaly areas is significantly greater than local atmospheric levels (0.037 percent), and at the control area (0.498 percent). The USGS notes that natural or man-made depressions (with or without tree kills), in this vicinity may be a risk to human health. The most visible effects have been the tree kill zones where carbon dioxide has accumulated to toxic concentrations in the root zone. However, a U.S. Forest Service ranger reported symptoms of asphyxia (March 1990) when he entered a snow-covered cabin near Horseshoe Lake.


The fourth case is briefly discussed on the USGS Volcano Hazards program. The brief information on common lethal carbon dioxide concentrations that are monitored in the East African Rift Zone. The significance of this information is the "sharp boundary" of high carbon dioxide and ambient air. The attached photographs show that lowering a torch several centimeters can cause the flame to go out. Additional information on sites listed here and some other volcanic CO2 incidents summarized on the International Volcanic Health Hazard site.


The fifth case represents an evaluation of indoor air quality at the Beverly Hills Unified School District (BHUSD). The Phylar Group, Inc evaluated the indoor air quality data collected by CTL Environmental Services, Inc. The action levels were determined using the standard risk assessment protocols developed by USEPA, and the California Environmental Protection Agency. The action level for carbon dioxide based on the class size was determined to be 1000 parts per million for the 8-hour time weighted average, and 2000 parts per million for the peak exposure. The triggering of an action level was noted as possibly not necessarily dangerous to human health, but may warrant sampling or more detailed evaluation.


The sixth case is summarized on an OSHA Hazard Informational Bulletin (June 5, 1996) regarding a fatality of a tractor-trailer driver. During a routine delivery to a restaurant supply company, an incomplete seal on the CO2 delivery system and a below ground fill station created dangerous levels to accumulate at the fill point.


The seventh case also is summarized on an OSHA News Release (July 31, 1996). The objective of the News Release was to present the dangers of oxygen displacement by carbon dioxide in decorative waterfalls and fountains. The one example presents the case where an employee adjusting the valves in a fountain pit lost consciousness. His partner also lost consciousness in a rescue attempt. A security guard and a passerby attempted a rescue but abandoned the attempt as they became dizzy. The Fire Department provided an adequate rescue, and both employees were treated and released.


The eighth case represents the summary of the findings by the U.S. Geological Survey and other domestic and foreign researchers on the release of carbon dioxide from two Cameroon lakes. The violent turnover of Lake Monoun (1984) and Lake Nyos (1986) resulted in approximately 1,800 human fatalities, and thousands of domestic and wild animals. The basic elements of a proposed degassing program, tentatively scheduled to start during 2000, is attached. The basic findings indicate that carbon dioxide from springs enters the bottoms of these highly stratified lakes creating high concentrations of trapped carbon dioxide at lower levels. The mechanism creating the violent overturn of the lower lake levels has not been defined at this point in time.


The ninth case represents gases from abandoned mines in the Eastern part of Russia. The Associated Press article describes the problems encountered in the town of Partizansk (pop. approximately 59,000) due to high carbon dioxide and associated low oxygen from the abandoned mines closed in 1996. The Russian officials had prohibited residents from using about 600 cellars. However, the residents have improvised novel ways of short trips to retrieve food from their cellars.


The tenth case is the Government of Saskatchewan Health and Safety Homepage on recent fatalities in water wells. Three incidents are briefly described regarding the potential asphyxiation dangers of servicing water wells. In the first example, a worker using strong acid to remove carbonate deposits in a shallow (10-feet) well created a reaction that released carbon dioxide that asphyxiated the worker. A second worker died when he attempted to rescue the first worker.


The eleventh case provides information from the Association of Local Government Engineers of New Zealand (ALGENZ) on gas risks from closed landfill sites. The two main gases are considered to be carbon dioxide and methane, with lesser amounts of trace gases. The source indicates that this gas will generally move 20 times more easy in a horizontal direction than in a vertical direction The hazards of future developments on these sites is also discussed. The specifics of fatalities are not identified, but the "Potential Hazards" Section notes that there has been asphyxiation in enclosed spaces in New Zealand and other areas.


The twelveth fatal accident was at a Department of Energy experimental test reactor in Idaho during July 1998. This involved an accidental release of carbon dioxide during routine maintenance that caused the one fatality and exposure to fifteen other workers.


Although, not quite a fatality, the following Center for Disease Control (CDC) summary shows health effects from elevated carbon dioxide.

"In June 2001, a man and a woman, both of whom were smokers, previously healthy, and aged 42 years, moved into a newly built, two-story home. Shortly after moving in, the woman noted episodic shortness of breath, lightheadedness, dizziness, and fatigue while in the finished basement. The man reported episodic mild confusion, poor concentration, headache, and blurry vision while working in the basement. Their symptoms always resolved within minutes of returning upstairs."

CDC Morbidity and Mortality Weekly Report, December 24, 2004