In Ireland and internationally, there has been much attention on the growing popularity of inhaled nitrous oxide (N2O), colloquially known as ‘laughing gas’ or ‘hippy crack’. Although the prevalence of nitrous oxide use is not routinely collected in Ireland’s National Drug and Alcohol Surveys, a web survey (N=4398) conducted in 2021 found that 23.3% of respondents had ever used nitrous oxide, while a 2022 study (N=1193) of attendees at music festivals in Ireland found that 28% had used it in the last year.1,2 The popularity of nitrous oxide as a recreational drug can be attributed to the fact that it is cheap, readily available, and undetectable on routine drug screening. Recreational users tend to obtain it in small silver canisters known as ‘whippets’ or ‘silver bullets’, which are attached to a palm-sized ‘nitrous cracker’ to fill a balloon, from which the gas is inhaled. However, as nitrous oxide is cooled to its gaseous form for inhalation, container mishandling can cause frostbite injuries to the face and extremities.

In an article3 published in February 2024 in the Irish Medical Journal, Murphy et al. discuss that over a 6-month period from September 2022 to March 2023, seven frostbite injuries due to recreational nitrous oxide use were managed by adult and paediatric burns services in Ireland. Although injuries tended to be small, they involved critical structures such as the hands or face. Presentation for medical care was often delayed, with one patient requiring ICU-level care for toxic shock syndrome. The mechanism of injury was most commonly associated with the filling of balloons from nitrous oxide canisters and subsequent freezing of the canister exterior. Larger commercial canisters tended to cause bilateral thigh and forearm burns, whereas single-use ‘bulb’ canisters were associated with smaller finger burns. The burden of care was significant, with two out of seven patients requiring debridement and grafting, and others attending for prolonged periods of dressings and/or rehabilitation.

In their discussion, the authors note that current legislation in Ireland allows for the sale of nitrous oxide canisters for industrial purposes. However, the Criminal Justice (Psychoactive Substances) Act 2010 prohibits its sale or importation for psychoactive properties.4 They recommend that more information about the risks and harms associated with nitrous oxide use be made available at music festivals and entertainment venues.

1    Mongan D, Killeen N, Evans D, Millar SR, Keenan E and Galvin B (2022) European Web Survey on Drugs 2021: Irish results. Dublin: Health Research Board. Available from: https://www.drugsandalcohol.ie/36571/

2    Ivers JH, Killeen N and Keenan E (2022) Drug use, harm-reduction practices and attitudes toward the utilisation of drug safety testing services in an Irish cohort of festival-goers. Ir J Med Sci, 191(4): 1701–1710. Available from: https://www.drugsandalcohol.ie/34860/

3    Murphy D, Leon R, Carr S and de Blacam C (2024) Frostbite injuries from recreational nitrous oxide use. Ir Med J, 117(2): 910–920. Available from: https://www.drugsandalcohol.ie/40522/

4    Department of Justice and Law Reform (2010) Criminal Justice (Psychoactive Substances) Act 2010. Available from: https://www.oireachtas.ie/en/bills/bill/2010/34/