Medical grade CO2 has 99.99% purity rating. Both Beverage and Food grade CO2 both have a 99.95% purity rating. Industrial CO2 has a 99.90% purity rating. The other .09 – 1% is made up of impurities such as hydrocarbons or nitrogen. The slight difference between Industrial-grade CO2 and Food grade CO2 is the type of test that are done to qualify CO2 as Beverage gas compared to Industrial-grade. Food grade CO2 is in fact Beverage grade CO2, they are equivalent. Its all about the purity of the gas. All CO2 is made the same (to the best of our knowledge). Its all about how the CO2 is stored, handled and transferred. The FDA has put compliance laws on Food aka Beverage grade CO2, making distributers store the gas in specific tanks just for Food or Beverage grade. Food grade CO2 is pure enough for human consumption based on FDA compliance. Food-Grade, anything (in the US) means special requirements on transport and handling, which implies more expense. So even though the same plant may produce it, the pipes leaving the plant have to be Food grade, the tanks the product goes into have to be Food grade. The non-food grade version will go through less expensive /less-maintained/less-cleaned pipes and into similarly treated containers. Medical grade CO2 is not reasonable to get for consumption purposes.
When talking about cylinders we must first consider high pressure vs. low pressure. HPA (High Pressure Air) tanks are pressurized up to the tank’s rating of 3000 psi or 4500 psi (Pounds per Square Inch). The pressure is then regulated through the tank’s regulator down to 850psi (High Output) or 450psi (Low Output). High pressure vessels are generally referred to as tanks, whereas Low pressure containers are generally referred to as dewars. Many people use the word “dewar” to describe a “liquid cylinder”, and vice versa. There are some key differences and they come in a wide variety of options.
While dewars might seem complicated at first, in reality they’re safe and easy to use once you understand the basics. If you’re interested in talking with an expert about how liquid CO2 trimming and sifting can radically improve efficiencies at your operation, contact us today to talk to one of our post-harvest processing experts.