Why in news?

• The Tamil Nadu government issued an advisory banning the use of liquid nitrogen in food and warned of stringent action against violators.

About Liquid Nitrogen

• Liquid nitrogen is a cryogenic liquid. It has a boiling point of –320°F (–196°C).
  • Cryogenic liquids are liquefied gases that have a normal boiling point below –130°F (–90°C). Liquid nitrogen has a boiling point of –320°F (–196°C).
• Liquid nitrogen is inert, colorless, odorless, non corrosive, nonflammable, and extremely cold.

Applications 

Medical applications

• It is used in cryotherapy to remove skin abnormalities; Cryosurgery (removing dead cells from the brain); Cryopreservation of blood; Cryopreservation of biological samples like eggs, sperm, and animal genetic samples.

Food applications

• Serves as a source of an extremely dry gas; Freezing and transporting of food products; Making ice cream.

Industrial applications

• Cooling of superconductors like vacuum pumps, and other equipment
• Quick freezing of water or pipes to let workers work on them when valves are not available.

Health Impacts

• Tissue Damage: The extreme cold of liquid nitrogen can cause cryogenic burns or frostbite if it contacts skin or mucosal membranes, which is a concern if ingested before completely evaporated.
• Internal Damage: Swallowing liquid nitrogen can lead to severe internal damage, including perforations in the stomach or intestines due to rapid expansion from liquid to gas.
• Asphyxiation: Liquid nitrogen expands 695 times in volume when it vaporizes and has no warning properties such as odor or color. The rapid expansion can also displace oxygen in the environment, particularly in enclosed spaces, posing a risk of asphyxiation.

https://www.mvsengg.com/blog/uses-of-liquid-nitrogen-its-working-principle/ 

https://indianexpress.com/article/lifestyle/food-wine/tamil-nadu-madurai-liquid-nitrogen-ban-smoking-biscuit-health-9296644/