A number of applications are based on treatments of food preservation, such as packaging or gasing of vegetables.
For example, gasing of some tuber vegetables (i.g. potatoes) prevents the growth of buds during the stocking period. In some extents, inert gases – which cause asphyxia – can be used, or some waste products produce typical decomposition gases such as methane and hydrogen sulphide.
Grain storage bins and cereal storage areas may produce carbon dioxide. Some fruits may release ethane, carbon dioxide and decomposition materials become dangerous in the nearby areas.
In industrial sausage factories, frozen products are cut by means of nitrogen, therefore they need to be equipped with suitable oxygen detectors to monitor if there are any leaks and safeguard operators' health.
Ammonia (NH3): when stocking vegetables and fruit it is indicative of deterioration due to decomposition.
Inflammable gases: In the productions of cooked food, such as sweets and bread, for example,
flammable gases are in form of fuel delivered to ovens.
Carbon dioxide (CO2): Carbon dioxide does not behave as a bactericide (unless in a very high percentage), but it can stop growth and proliferation of the main biological agents which can affect foodstuffs.
Also the effect of carbon dioxide is clear at chemical level: in fact, after dissolving in the product, this gas develops a mild acid action able to denature those enzymes whose action may change the foodstuff scent in time and interact with the other, either animal or vegetal, ingredients so reducing spontaneous modifications.Hydrogen sulphide (H2S): to some extent, it is due to a condition of decomposition of organic matters, just like ammonia.
Nitrogen (N): Nitrogen enables a proper proportion of all the other gases which are part of the modified atmosphere mixture required for packaging; it excludes the presence of oxygen and slows down the negative changes due to enzymatic and microbiological activities.
NH3: colourless, with an irritating, sharp smell, inflammable, toxic. Ammonia irritates the mucosa of the conjunctiva, nostrils and pharynx through a scalding action. Moreover, ammonia has a general scalding action.
Inflammable gases: in smaller concentration even than LEL with regard to the volume they explode in presence of a minimum flash source resulting in often serious consequences for people and things
CO2: poisoning due to carbon dioxide, risk of asphyxia due to lack of oxygen.
H2S: colourless gas stands out for its characteristic smell of rotten eggs. A low-concentration exposure causes eye and throat irritation, cough, acceleration of breathing and fluid formation in the respiratory ways. High concentrations kill the olfactory nerve so making impossible to smell its disgusting odour, and may cause unconsciousness in few minutes
N: like carbon dioxide, high concentrations of gas nitrogen in air may cause asphyxia.