Carbon dioxide gas is used in many food industries, particularly in those producing beverages. It is primarily used for carbonation of packaged drink products as well as a blanket gas in storage to exclude oxygen, which can cause deterioration of a product’s shelf-life. Breweries are able to produce their own CO₂ as part of the fermentation process. The CO₂ can be collected, liquefied and stored prior to vaporisation for use in product. In many cases breweries can be self-sufficient in CO₂supply. For those industries without a regular source, CO₂ can also be collected from boiler flues or generated in diesel plants. Critical for all beverage producers is that the CO₂ is of high purity with little oxygen contamination.