The Advisory Council on the Misuse of Drugs’ (ACMD) Technical Committee has considered the emerging issue of nitrous oxide abuse after the British Compressed Gases Association (BCGA) raised its concerns on this abuse to the ACMD.
Whilst the harmfulness of nitrous oxide does not seem to warrant control under the Misuse of Drugs Act 1971, the ACMD has been compelled to offer this public health safety advice as a part of its remit.
Home Office Drugs Misuse data for 2013-2014 indicated that 7.6% of 16-24 year olds in England and Wales reported nitrous oxide use in the past year, making it the second most popular recreational drug after cannabis.
There has been a recent upsurge in the recreational use of nitrous oxide and it is now commonly available in certain clubs and increasingly at music festivals, where it is often purchased in the form of gas-filled balloons. A number of festivals have a “no legal highs” policy, though there appears to be a tolerance to the sale and availability to nitrous oxide.
When inhaled, the gas induces a brief period of euphoria, which may be accompanied by “tears of joy.” This appears to be due to a brief activation of opiate systems in the brain. Users often wish to repeat their positive experiences with the gas, although there is no firm evidence of physical dependence. Nitrous oxide is an asphyxiant at high concentrations. At lower concentrations, exposure may cause central nervous system, cardiovascular, hepatic, hematopoietic, and reproductive effects in humans.
It appears to have few, if any, short term adverse effects, other than mild headaches for some individuals. Long term abuse can cause peripheral sensory neuropathies. Long term abuse can also cause vitamin deficiency and related anaemia as a result of the inactivation of Vitamin B12 in the body by the gas.
Deaths linked to nitrous oxide are rare (~15 deaths per year in USA; 1 in the UK in 2011 and 5 in the UK in 2010). These have been due to asphyxiation resulting from hypoxia (lack of oxygen). A number of the deaths involved the use of nitrous oxide in an enclosed space.