Packaging gas
A packaging gas is used to pack sensitive materials such as food into a modified atmosphere environment. The gas used is usually inert, or of a nature that protects the integrity of the packaged goods, inhibiting unwanted chemical reactions such as food spoilage or oxidation. Some may also serve as a propellant for aerosol sprays like cans of whipped cream. For packaging food, the use of various gases is approved by regulatory organisations.
In the food sector, the gas composition—typically N₂/CO₂ and, depending on the product, O₂—is selected to manage respiration and microbial growth; the atmosphere is applied by flushing the pack or by in-line injection. FAO guidance describes principles and uses, while manufacturer application notes provide examples of common gases and supply arrangements used in industry.
Their E numbers are included in the following lists in parentheses.
Inert and Nonreactive gases
These gas types do not cause a chemical change to the substance that they protect.- argon, a inert gas used for canned products
- helium, a inert gas used for canned products
- nitrogen, a nonreactive packaging gas and propellant
- carbon dioxide, a nonreactive packaging gas and propellant
Propellant gases
- chlorofluorocarbons known as CFC, now rarely used because of the damage that they do to the ozone layer:
- * dichlorodifluoromethane
- * chloropentafluoroethane
- nitrous oxide, used for aerosol whipped cream canisters
- octafluorocyclobutane
Reactive gases
- oxygen, used e.g. for packaging of vegetables
- hydrogen
Volatile gases