Liquid nitrogen in food: The hidden danger behind smoke-filled desserts and frozen treats
In 2024, the Karnataka government banned the use of liquid nitrogen
“while serving food”, after a boy died from consuming it from a paan
vendor. The easy availability of the substance is a major cause for
concern, and stricter regulations and safety experts. The government does not restrict its use in cooling or preparing food.
Some agencies like Pai Air Products, with units in Mysuru Road and
Peenya, have stopped selling liquid nitrogen to customers buying it for
freezing simple snacks like biscuits, after a recent mishap. “We sell
about 1,000 litres of it per day.
Anyone with a cryogenic cylinder can purchase it. It does not require
any special permits, unless one is installing a tank,” says Adith Pai.
Apart from restaurants and chefs, it is also bought for freezing animal
semen for artificial insemination and for industrial purposes like shrink fitting and laser cutting.
Better regulation
Rangaswamy C E, president of the Karnataka Beedhi Badhi Vyaapari
Sanghatane Okkuta, told Metrolife that none of the vendors under the
association uses liquid nitrogen.
However, he shared that the GBA has failed in setting up an efficient
system to regulate and support street food vendors. Officials from GBA
did not respond to calls from Metrolife.
Chef Johnson Ebenezer, who runs an experimental farm-to-fork restaurant, Farmlore, uses the substance extensively in his menu. The
restaurant gets its liquid nitrogen from Pai Air Products.
Cryogenic cylinders with capacities of 10 and 25 litres are sent to the
agency to be filled, for Rs 71 per litre. “Using unsuitable containers
that are not designed for cryogenic liquids can increase the risk of
pressure build-up and accidents,” says Dr Anupama N K, a senior gastroenterologist who consults at a prominent hospital in Hebbal.
The boiling point of nitrogen is -196 C, whereas a regular freezer is about -18 C. “So it is quite extreme,” notes Ramesh Agarwal, CEO of Food Safety Works.
Quick freezing
While the substance does not influence taste in any way, the speed at
which it freezes food makes it convenient for chefs and allows for
experimentation.
The theatricality of the heavy smoke, the liquid evaporating, is, of
course, the main draw. “As per FSSAI guidelines, the food cannot be
served to the customer until all the liquid nitrogen has evaporated. In
some cases, when the substance gets rapped in the food, it’s easy to miss.
That is when it is tragic,” explains Johnson. He adds that vendors or
chefs using it must go through proper training on safe practices,
because it’s tricky to handle.
Exercise caution
Even a small amount left in the food can cause severe burns to the
mouth, throat or stomach, but it is perfectly safe if handled the right
way, notes Dr Anupama. “Never eat or drink anything that is still
producing thick white fog or visible vapour as it indicates that the liquid nitrogen has not yet
fully evaporated,” she states, adding that touching it with one’s hands
can lead to frostbite and tissue damage.
If someone swallows it and experiences severe pain, burns, difficulty
breathing or swelling, immediate medical attention can prevent serious
complications. “If it reaches the stomach before it has fully
evaporated, it turns into gas, which causes severe bloating that can rupture the stomach. The lips, tongue, throat and oesophagus, which come in contact with it
first, will also be affected. Even inhaling large amounts of nitrogen
gas in poorly ventilated areas, where oxygen is low, can lead to
dizziness, headaches, confusion, shortness of breath and loss of consciousness,” she points out.