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Health Hazard Acute and Chronic: Concentration in excess of 1.5% carbon dioxide may cause death. At higher concentrations, displaces oxygen in air below levels necessary to support life.
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Steps if Material Released/Spill: Ventilate indoor areas well to avoid hazardous CO2 concentrations. Ventilate area well & avoid contact w/cold vapors/dry ice. CO2 is heavy gas & will remain in low spots w/out assisted ventilation.
In September 2004, in anticipation of a power outage during the aftermath of Hurricane Ivan, a man aged 34 years in Mobile, Alabama, purchased a 100-lb block of dry ice from a local ice house. The block of dry ice was divided into four equal parts and packaged in brown paper bags, which were placed in the front seat of the man's pickup truck. The windows were closed, and the air conditioner was set to recirculate air inside the cab of the truck. After driving approximately one quarter mile from the ice house, the man had shortness of breath; his breathing difficulty increased as he drove the next mile. The man telephoned his wife and asked her to call 911. He then pulled his truck into a parking lot, parked, and lost consciousness. His wife drove to the parking lot and located her husband's truck; immediately after she opened the door to the vehicle, her husband began to awaken.
Emergency medical services personnel arrived soon afterward. They determined that the man's vital signs were normal and he required no further medical evaluation. Although the man complained of a headache for the next 24 hours, he recovered completely.
Dry ice has a temperature of -109.3ºF (-78.5ºC) and can be used to keep perishable foods cold (1). As dry ice melts, it undergoes sublimation (i.e., direct conversion from a solid into gaseous CO2, bypassing the liquid state). Improper ventilation during use, transport, or storage of dry ice can lead to inhalation of large concentrations of CO2 with subsequent harmful effects, including death (1,2). Previous reports have described illness and death caused by occupational exposures and unintentional nonoccupational exposures to dry ice in enclosed spaces such as automobiles and submarines (1,2).
Under normal conditions at ambient temperature, CO2 is a colorless, odorless gas and a simple asphyxiant that displaces oxygen when inhaled. As the inhaled concentration of CO2 increases, more oxygen is displaced from the lung alveoli, where gas exchange takes place. The central nervous system (CNS) tightly regulates dissolved CO2 in the blood; changes in the partial pressure of CO2 cause changes in the respiratory rate. An increase in CO2 concentrations triggers an increase in respiratory rate, causing further uptake of CO2, which can ultimately lead to signs and symptoms of hypoxia and hypoxemia, including headache, confusion, disorientation, and death. Respiratory and CNS changes can occur within seconds of exposure to high levels of CO2, suggesting that the toxicity of CO2 might be related to systemic effects that are not fully understood.
Dry ice gives off CO2 into the air. So if dry ice has been in a closed car, van, or room for more than 10 minutes, open the doors and windows before entering. Otherwise, you will experience difficulty breathing. Leave the area immediately if you start to breathe quickly or your fingernails and lips turn blue.
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Dry ice changes to CO2 gas as it sublimates (melts). Do not use or store in a confined space. [like your fridge!] Do not place in airtight containers. Airtight containers may explode as dry ice converts to CO2 gas.
