Food Protection Trends - May/June 2021 - 293

Dena Ali,1* Jeffrey M. Farber,1 JinHee Kim,2,3
Naghmeh Parto2 and Ray Copes3

PEER-REVIEWED ARTICLE
Food Protection Trends, Vol. 41, No. 3, p. 293-304
Copyright© 2021, International Association for Food Protection
2900 100th Street, Suite 309, Des Moines, IA 50322-3855

Canadian Research Institute for Food Safety, Dept. of Food Science,
University of Guelph, Guelph, Ontario, Canada. N1G 2W1
Public Health Ontario, Toronto, Ontario, Canada M5G 1V2
3
Dalla Lana School of Public Health, University of Toronto,
Toronto, Ontario, Canada, M5T 3M7
1*

2

A Qualitative Risk Assessment of
Liquid Nitrogen in Foods and Beverages
ABSTRACT
Smokey liquid nitrogen (LN2) infusions are one of
the latest eye-catching food trends. With its ability
to create fog-like effects and flash freeze foods, LN2
has become popular for use in ice cream, snacks, and
cocktails recently. Although perceived to be harmless,
there are incidents of consumers suffering adverse
health effects after consuming foods prepared with LN2.
Thus, a qualitative risk assessment was undertaken to
estimate the potential risks to consumers. Through an
analysis of gray and scientific literature, case reports
related to inhalation, ingestion, and contact with LN2
were reviewed for relevant information. It was found that
inhalation of LN2 vapors could potentially cause rare,
but serious, injuries such as respiratory distress and
asphyxia. Ingestion injuries, which typically result after
consuming LN2 before it fully evaporates, often include
gastrointestinal barotrauma and rupture. Lastly, when skin
or tissues come in contact with LN2 for more than a short
period of time, frostbite can occur. To reduce the risks
posed to consumers, it is recommended that (i) vendors

are properly trained to handle and serve LN2, (ii) patrons
are given clear instructions on how to safely consume
such treats, and (iii) regulatory agencies put appropriate
regulatory interventions into action as needed.

INTRODUCTION
Ambient air is composed of approximately 78% nitrogen
gas (26). Through a process called fractional distillation,
nitrogen gas in the air can be separated from the other
components of air and converted into its liquid state (3,
26). Nitrogen in its liquid form is referred to as liquid
nitrogen (LN2) and is characterized as being inert, colorless,
noncorrosive, and nonflammable (1, 26). For nitrogen
to remain in its liquid state, it must be kept at very high
pressures and extremely low temperatures (3). If LN2 comes
in contact with anything above its boiling point (−196°C or
−320.1°F), it will transform back into nitrogen gas (3, 26).
Due to its cold temperature, LN2 has become widely
adopted for its rapid cooling and freezing applications (38).
From flash freezing foods to preserving biological specimens,
LN2 serves many different functions in various industries

*Author for correspondence: Phone: +1 519.982.3767; Email: alid@uoguelph.ca

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