It's a gas consumed by millions every day. Plants need it for survival. In fact we exhale it with every breath we take. Virtually every restaurant uses Carbon Dioxide (CO(2)) in bulk form to put the fizz in soft drinks. It's used as an important ingredient in certain fire extinguishers. Carbon dioxide is a heavy gas and displaces oxygen, settling at the lowest levels. It is odorless, colorless, and cannot be detected by human senses. Exposure can lead to dizziness, unconsciousness, even death.
Several deaths involving Carbon Dioxide CO(2) have occurred at quick-service restaurants in recent years involving employees, patrons, and CO(2) delivery drivers. This past fall, an 80-year-old customer in Florida died from asphyxiation in the women's restroom when the gas seeped into the room while the restaurant's CO(2) tanks were being refilled. A line used to funnel excess carbon dioxide out of the restaurant became disconnected. Nine others were sickened in the incident, including three firefighters and two others who were found unconscious trying to help the woman, who died, and were taken to an area hospital. In another incident, also in Florida, an 18-year-old McDonald's employee and a CO(2) delivery driver died from asphyxiation from a leak in the connection with a fill port located in a small internal room.
The effects of CO(2) exposure can strike without warning and cause serious physical reactions, including:
More serious physical effects of elevated exposure and a threat to health and life:
All of the above symptoms may occur without warning and in the presence of normal oxygen levels.
Many of the problems seem to be related to leakage of older or retrofitted installations and fill ports or lines in or near enclosed spaces, below ground stairwells and basements, but not confined to those specific conditions. In some cases it was equipment failure, in others it was human error. All of these tragedies have one thing in common; they could have been avoided.
OSHA issued a memorandum regarding potential CO(2) asphyxiation hazards when filling stationary low pressure supply systems. In that memo the following recommendations were made to "minimize the development of hazardous conditions that may cause accidents or fatalities involving CO(2) intoxication":
There are many monitoring devices on the market that will provide alarms when certain levels of carbon dioxide are detected. They should be mounted at the lowest level near the fill ports and storage tanks. Consult with your CO(2) supplier or safety professional for what may be suitable for your particular situation. Keep in mind that deadly accidents have occurred with devastating consequences. If you have CO(2) fill ports or storage tanks in tight enclosed quarters, lower levels, or have older systems or systems that have not been inspected by qualified personnel, have them inspected immediately. Install monitoring systems to detect unhealthy levels of carbon dioxide. With each tragic accident, we are reminded that the victims were innocent; unaware that their oxygen, the sustenance of life, was being sucked away. They had no chance because they couldn't smell it, taste it, or sense it in any way. Don't let it happen to anyone else.
For further information on stationary low pressure, carbon dioxide supply systems and related topics, the following Compressed Gas Association Inc. (CGA) pamphlets should be consulted. These pamphlets are designed to assist personnel involved in transferring liquid carbon dioxide, designers, engineers, safety and training personnel, distributors, restaurant personnel, other users, inspectors and all interested parties.
CGA G-6.5-1992, Standard for Small Stationary Low Pressure, Carbon Dioxide Supply Systems
CGA G-6.4-1992, Safe Transfer of Low Pressure Liquefied Carbon Dioxide in Cargo Tanks, Tank Cars, and Portable Containers
CGA G-6.3-1995, Carbon Dioxide Cylinder Filling and Handling Procedures
CGA G-6-1984, Carbon Dioxide
CGA G-6.2-1994, Commodity Specification for Carbon Dioxide
CGA G-6.6-1993, Standard for Elastomer-Type Carbon Dioxide Bulk Transfer Hose