Spotlight on... Recreational use of nitrous oxide (laughing gas)

This spotlight presents the key findings of the Recreational nitrous oxide use in Europe: situation, risks, responses which is the first section of the report 'Recreational use of nitrous oxide — a growing concern for Europe'.

Nitrous oxide is a gas that is inhaled recreationally for its rapid but short-lived feelings of euphoria, relaxation, calmness, and sense of detachment.

While it has been used for almost 250 years, its use has increased in some European countries since 2010. This became a particular concern from around 2017–18, when it became available in more shops and in larger quantities.

The popularity of nitrous oxide is explained by its easy availability, low price, short-lived effects, and the general perception by users that it is a relatively safe and socially acceptable drug.

In most cases, small cartridges of the gas intended to make whipped cream are used to fill party balloons, from which the gas is inhaled. The canisters are bought in brick and mortar shops as well as online. Suppliers have also started selling larger cylinders of the gas, deliberately targeting the recreational market — making the gas significantly cheaper and promoting broader, as well as more regular and heavier, use.

The vast majority of people do not use nitrous oxide. Those that do typically use relatively small amounts infrequently. Most users inhale small quantities of nitrous oxide occasionally, perhaps one to three balloons in a session, a few times a year. Although it is not possible to define a ‘safe’ level of use, and this kind of use is not risk-free, it appears to pose limited health risks compared with more intensive patters of use. Use may also vary significantly within a country. Most use of nitrous oxide is by young people, including teenagers.

Nitrous oxide is typically used with friends, but it may also be used alone, especially with heavier use. It is used in a range of settings, including outside in public spaces (such as parks), in parked cars (so called ‘car parties’), at home, at private parties, in nightclubs, and at music concerts and festivals.

Common adverse effects from using small amounts include dizziness, light-headedness, disorientation, headache, and a generalised tingling sensation. Nausea and fainting may also occur; as may temporary loss of co-ordination and balance. Some effects are from hypoxia caused by a temporary lack of oxygen, which may also cause seizures.

The adverse effects are generally minor and resolve within a short period of time after the user stops breathing the gas. However, some effects, such as light-headedness, dizziness, and general impairment can continue for 30 minutes or so. Using larger amounts of gas in a single session causes a higher number of these adverse effects.

Acute poisoning requiring medical treatment is relatively uncommon. Typically, it involves short-lived disorientation, loss of consciousness or fainting, as well as injuries from falls caused by this or from loss of co-ordination and balance while intoxicated. Occasionally, hallucinations may also require treatment.

Due to disorientation and general impairment, people using nitrous oxide should not drive, ride bikes or scooters, or operate machinery. Some people do not view using nitrous oxide while driving as dangerous.

There is also a small, but significant, increase in the number of people who use greater quantities of the gas more frequently and for longer periods of time. Some develop problematic use as a result. The short-lived effects of the gas are often cited as a reason for further use in the same session.

Regular and heavy use of the gas can also cause serious damage to the nervous system (neurotoxicity).

Initially, symptoms usually include paraesthesia — which means abnormal sensations, typically tingling or pricking (‘pins and needles’), in the hands, arms, legs, or feet, and which can also occur in other parts of the body. This may be caused by damage to the sensory nerves responsible for transmitting sensations, such as pain and touch, and can progress to numbness. Damage may also involve nerves that are responsible for controlling muscles, leading to muscle weakness, loss of balance, and difficulty in walking. The damage can involve both the peripheral nervous system and central nervous system, especially the spinal cord. Damage may progress to an inability to walk.

Typically, the damage is at least partially reversible, especially if identified and treated early. Some individuals may be left with sensory or functional damage. Rare cases of permanent paralysis have been reported. Sometimes, patients stop treatment, so the long-term outcome is unknown.

The use of large cylinders to obtain the gas can also cause severe frostbite (burns caused by exposure to freezing) and lung injuries due to their high pressure. These injuries require urgent medical treatment.

Deaths involving nitrous oxide are rare. In most cases, the cause is accidental asphyxiation from breathing the gas using a mask or plastic bag over the head without sufficient oxygen.

There is limited information on effective responses. In most cases, countries have used a range of measures to restrict the supply of nitrous oxide and provide targeted health promotion, including harm reduction advice.

Targeted health promotion, including risk communication, should provide timely, clear, credible, and consistent evidence-based messages that raise awareness, understanding, and practical actions that can be taken. This may include communications with users as well as parents and guardians, and should come from trusted sources.

Simple, evidence-based, harm reduction advice may help prevent both common adverse effects and the more serious risks linked to nitrous oxide. It can also be used to inform people what to do in an emergency, and how to seek additional information and help.

Nitrous oxide has important, wide-ranging, medical, industrial, commercial, and scientific uses, including as an analgesic and anaesthetic in medicine and as a food additive. Any response to nitrous oxide needs to consider the widespread legitimate uses of the gas by industry, healthcare, and consumers. Currently, there are few, if any, alternatives to the gas for these uses.

Littering of used cartridges, balloons, and cylinders has been highlighted as an issue in some areas. This is unsightly, incurs clean-up costs, and is harmful to the natural environment. Used cylinders pose a risk of explosion during waste processing if disposed of in general waste. Importantly, cartridges and cylinders are steel and can be recycled.

Nitrous oxide is a potent greenhouse gas and major cause of the destruction of the ozone layer. The contribution from recreational use is minor compared with other sources, but requires research.

Our understanding of use, harms, and effective responses is limited, partly because this level of recreational use is relatively new. Monitoring needs to be strengthened and research is needed in areas such as epidemiology, supply, pharmacology, toxicology, as well as the effectiveness of treatments and response measures.