Inhalation of nitrous oxide: ANSES recommends improving regulations and better informing the public about potential health risks

Nitrous oxide, commonly known as ‘laughing gas’, is a colourless gas with a slightly sweet smell and taste. Nitrous oxide is used in the medical field for its analgesic properties. It is also used as a propellant in dispensers for making whipped cream, and nitrous oxide canisters are sold in shops and on the internet, which means that they are accessible to the general public.

The practice of inhaling nitrous oxide causes poisoning that can sometimes be serious

The practice of inhaling nitrous oxide recreationally has spread rapidly, particularly among young people, because of its euphoric effect. However, its use is not without risk, as shown by a toxicovigilance study carried out by ANSES on the basis of data from poison control centres (CAPs).

Between 1 January 2017 and 31 December 2019, 66 nitrous oxide poisonings were recorded by the CAPs. Most of them concerned young men. More than half the users were aged between 20 and 25. Hauts-de-France, Île-de-France and Occitanie were the most affected regions. The nitrous oxide used was of a non-medical type contained in over-the-counter canisters for food use, and was inhaled using balloons. The individuals reported taking quantities ranging from a few canisters in the course of an evening – often in conjunction with alcohol or other drugs – to several hundred a day, over several months in some cases.

Out of 66 cases, 42 reported at least one neurological or neuromuscular symptom, such as paraesthesia, tremor in the extremities and muscle pain. Four people with chronic use had symptoms suggestive of nerve damage in the limbs. In this study, five people experienced serious symptoms. One patient suffered cardiorespiratory arrest, and heart disease was later discovered in hospital. Two others experienced convulsive episodes, with one person falling into a coma and suffering myoclonus symptoms (brief involuntary muscle twitching or jerking). The two remaining patients used nitrous oxide chronically, inhaling from 10 to 40 canisters a day, and had neurological symptoms.

Regulating access to and labelling of nitrous oxide in food containers

While regulations on medicines and narcotics apply when nitrous oxide is used medically, its food use as a compression gas in whipped cream dispensers is permitted, as it is then considered a processing aid and food additive. Such regulations take no account of how these products are misused.

ANSES thus stresses the need to regulate access to and labelling of nitrous oxide for use in food. A discussion should follow on from the bill adopted in December 2019 by the Senate, which aims to protect minors from the harmful uses of nitrous oxide by limiting the quantities for sale, banning its sale to under eighteens and implementing special labelling.

In France, municipal by-laws have been passed to prohibit the sale of nitrous oxide to minors and its consumption in public places.

Improving information for consumers as well as youth and health professionals to prevent health risks

Since it is sold over the counter and its effects are short-lived, users perceive the misuse of this substance to be harmless and innocuous, and are not aware of and/or do not fully appreciate the serious risks involved.

The Agency therefore recommends better informing young consumers on the proven hazards of inhaling nitrous oxide by working with school nurses and doctors, through community organisations working with schools and universities, and via targeted communication in party venues. Such outreach efforts should also target health practitioners, including paediatricians, general practitioners, psychologists, child psychiatrists, neurologists, occupational physicians and scientific organisations.