If you need an evaluation of carbon dioxide hazards (CO2) in food processing discussed in this article call us at 1-800-344-4414 or email us at firstname.lastname@example.org for details and a free estimate.
Written by Robert E. Sheriff, CIH, CSP, President
May 1, 2018
All living things need Carbon Dioxide for their life processes (plants take in CO2 and release oxygen. Animals and humans take in oxygen and release CO2.) At the same time, Carbon Dioxide can be hazardous to the health of us humans. Carbon Dioxide is also known as the “Greenhouse Gas” since it is the main element of life and growth for plants. Carbon Dioxide is also essential for human existence. Our natural breathing reflex is not triggered by a lack of oxygen in our system; it is caused by a build-up of Carbon Dioxide. However, too much carbon dioxide in the air we breathe (I’ll talk about sources later) can trigger excess breathing rates causing us to hyperventilate. Further, if CO2 gets very high, it can replace the oxygen in the air and cause asphyxiation.
How can the CO2 levels get so high they replace the oxygen and cause us to hyperventilate?
Hyperventilation can result from a build-up of CO2 in a building that is closed up and/or too many people (exhaling CO2) or other sources of carbon dioxide without adequate make-up air. This can possibly result in hyperventilating but it is unlikely to be life threatening.
There are a number of situations where high CO2 levels are possible and be dangerous to your life and health.
OSHA has established an acceptable Permissible Exposure Limit (PEL) for an 8-hour day of 5,000 ppm (www.osha.gov/law-regs.html). The American Conference of Governmental Industrial Hygienists (ACGIH) also recommends a 15 minute Short Term Exposure Limit (STEL) of 30,000 ppm (www.acgih.org/forms/store/CommercePlusFormPublic/Search?Action=Feature.
Where can you get levels of Carbon Dioxide above 5,000 ppm or 30,000 ppm?
Some of the most likely places are in food processing. One common place is where “dry ice” is used. Dry ice is simply Carbon Dioxide in a solid state. In open air, it will rapidly melt into Carbon Dioxide gas. Achieving 5,000 ppm is not difficult where dry ice is used.
Another likely place is in packaging of carbonated beverages. As “soda” or “pop” is bottled or canned, the liquid beverage is added to the containers and then concentrated Carbon Dioxide is forced under pressure into the liquid. Leakage or spillage to some extent always occurs and without adequate ventilation, the excess CO2 can get into the workspace where workers are situated increasing the levels of Carbon Dioxide to 5,000 ppm or higher.
Another location is where liquid Carbon Dioxide is used to flash freeze foods or using dry ice to keep them frozen. Again, the gas released can get into a worker’s breathing zone and exceed the safe limits.
There are locations in food processing and other industrial processes where Carbon Dioxide is used to “inert” the atmosphere to intentionally remove the oxygen to prevent fire or explosion. This is mostly done in closed vessels but such vessels are often opened to sample the contents, or remove the product, or leak, thus releasing the Carbon Dioxide gas into the occupied space.
We have even found excessive amounts in excess of 50,000 ppm in a refrigerated warehouse where Carbon Dioxide was the refrigerant. The high level of CO2 was due to an open vent in the storage tank that would release CO2 every time the sun hit the storage tank and cause the CO2 to expand. The vent alarm on the tank had malfunctioned.
These are by no means all the places where workers could be exposed to elevated Carbon Dioxide, but are the more common sources of potential worker exposure in food processing.
Sampling through the use of direct reading meters and personnel monitoring can determine whether OSHA limits or safe worker exposure levels have been exceeded. Contact us by e-mail (email@example.com) or phone 800-344-4414 for further details and assistance.
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