Knowing the risks of compressed air contamination in a food processing plant is important. Air is not as clean as it appears to be. Untreated compressed air contains many potentially harmful or dangerous contaminants which must be removed, or reduced to acceptable levels, in order to protect the consumer and provide a safe and cost effective production process. Along with moisture and particulate matter, inlet air to a compressor generally carries 5 to 50 bacteria per ft³. Therefore, a 75 hp compressor with a capacity of 300 SCFM takes in 100,000 to 1 million bacteria each hour. These bacteria are compressed along with the air and begin their journey through the compressed air system. Introducing this type of microbial contamination to food products is very risky and would be considered a lack of control by the facility. Understanding how to operationalize the treatment of compressed air in a food production facility will help ward off that risk.
Where Compressed Air Contacts the Food
Sometimes it is not apparent where the compressed air is contacting the food. Working surfaces like counters and conveyors are obvious and manageable contact points. However, compressed air is invisible and leaves no visible trace of where it contacts the food, other food contact surfaces or the packaging. Without adequate hurdles and physical barriers in place the microbial, particulate, and (in some cases) compressor oil contamination is left behind after the air dissipates.
Examples of processes that provide direct and indirect contact points are:
• Air Knives
• Pneumatic Exhaust (i.e., cylinder exhaust)
The image below shows a typical air knife application.
This is Part 2 of a 6 Part series on Compressed Air Contamination in Food Plants. Below are links to the rest of the series.
This series was written by Lee Scott, Market Development Manager, Parker Hannifin