Walking the streets of London on a Saturday or Sunday morning, it would almost be impossible to miss the discarded silver canisters of nitrous oxide littering the streets, remnants of the previous night. From Shoreditch to Dalston to Brixton, “NOS”, as it is commonly known, has become almost synonymous with the city’s nightlife scene.
In November 2023, after years of trying to control nitrous oxide (also colloquially known as “laughing gas” or “whippits”), the UK Home Office officially classified it as a Class C substance under the Misuse of Drugs Act 1971, making possession illegal. But despite a high-publicised crackdown, all evidence indicates that the harms associated with nitrous oxide have only increased.
According to the Government’s Crime Survey, the number of 16-24 year olds consuming nitrous oxide was 85% lower in 2024/25 than the data’s peak in 2019/20, and 79% lower for all adults. Yet, the number of children in treatment for solvent and inhalant misuse, which includes nitrous oxide, has nearly tripled in just a few years, from 329 in 2021 to 2022 to 919 from 2024 to 2025. Nitrous oxide was responsible for 6% of all cases of children in drug and alcohol treatment between 2024 to 2025, compared to just 3% between 2021 to 2022.
Additionally, in January 2026, the solvent and gas misuse charity Re-Solv said it had seen 50-70% increase in nitrous oxide abuse support requests in the last two years, with the average age of service users being 25. Meanwhile, a recent Irish study identified an “alarming” surge in young people suffering spinal cord damage linked to NOS use, with 14 cases recorded between 2021 and 2024, compared to none in the previous eight years.
Who is using NOS?
Although official Government data shows less people using nitrous oxide, Police and Border Force data tells a different story. It shows a dramatic increase in seizures: 6,223 incidents in the year ending March 2025, a 143% rise on the previous year and the highest since records began in 2018, and a 2,185% increase in the quantity seized, up to 4.19 million 8g cartridges.
Almost all of these seizures were by police forces, according to the Home Office. A major reason for such a stark rise is that reclassification of nitrous oxide to a Class C substance enabled police forces to make more consistent seizures.
According to Sorcha Ryan of Bristol Drugs Project, nitrous oxide becoming part of the Misuse of Drugs Act largely impacts suppliers, meaning those who were supplying illegitimately may have been encouraged by the law change to stop. However, while the legislative change may have deterred people who used nitrous oxide recreationally or opportunistically, those who used it problematically – so those who struggle with their mental health, have experienced trauma or any other usual contributing factors to how people experience drug related-harm – are likely still doing so. Today, a large amount of nitrous oxide appears to be getting consumed by a smaller proportion of people.
“It definitely appears, from the data we’ve got available, that nitrous oxide use is becoming more concentrated in that demographic,” Ryan told talkingDrugs. “Those opportunistic NOS takers aren’t getting those opportunities quite as much, but the people who were at risk of dependence from any substance are now experiencing those greater levels of harm.”
This cohort of people is much more likely to use nitrous oxide frequently – perhaps on a daily basis – rather than sporadically. Prolonged use is what causes nerve and neurological damage, because it affects how the body absorbs Vitamin B12. “When people use NOS over a prolonged period of time, they may get tingly fingers or lose sensation in their fingers and toes,” explained Ryan. “Over time, if someone continues doing that, they will potentially lose mobility.”
How are people using NOS?
This is true for Alice*, a 26-year-old Londoner who uses nitrous oxide recreationally. Since the law changed, she said she uses it much less frequently. This is because the small 8g canisters became less available, replaced by larger canisters that have become “the standard”.
There is very little data on this shift from smaller canisters to large “SmartWhip” style canisters, which contain around 600 grams of nitrous oxide per can. However, a Home Office official confirmed to Talking Drugs that there appears to be a trend towards larger canisters and some police forces have suggested they have seized more large canisters since the ban.
According to David Hurren, former president of the British Compressed Gas Association, this trend began before the legislative change in 2023. SmartWhip, the most commonly-sighted brand of these larger canisters, was formed in 2019. However, recent reports from waste management companies about large explosions, and the BCGA – which last month raised concerns over large canisters of nitrous oxide being imported illegitimately into the country – suggest these larger canisters are becoming more widespread.
SmartWhips exacerbating harms
While the harms associated with nitrous oxide tend to stem mostly from prolonged use, there are few unique harms linked to the rise in larger canisters. While Alice takes nitrous oxide less frequently, when she does, she does so in bigger quantities.
“[The large canisters] let you have a much bigger dose,” she said. “Whereas before you’d put one, maybe two [8g canisters] into a balloon, now you can do whatever.” This, said Ryan, has a huge immediate risk. “People are making enormous balloons, which are much more risky in terms of passing out and not getting enough oxygen,” she explained.
Using large canisters makes it much harder to keep track of how much someone has consumed in one session, Ryan added. “If you had a box of the small canisters, you could see the box getting empty, and you know how much you’ve used over the course of the night,” she said. “But with big canisters you can’t see inside it – and it’s easy, particularly with a drug like NOS that can be quite compulsive, to do much more in a single night.”
Another huge risk is that people tend to skip using balloons all together and consume straight from the canister. “This poses really significant risks if it’s dispensed too quickly, because it will be really cold when the gas goes from being pressurised to unpressurised, which can cause frostbite and frost burns in someone’s mouth or lungs,” said Ryan.
A report by The Londoner in April found that a spate of cold burns across the capital were linked to the use of large nitrous oxide canisters, often resulting in surgery to cut away the dead flesh, skin grafts and permanent scars for the victims.
Beyond the people who use drugs, large nitrous oxide canisters pose an increased social and environmental risk. This is because they are prone to exploding, and are classed as hazardous waste. But rather than being disposed of via specialist commercial collections, they are left in parks and roadsides or placed in general rubbish and recycling bins. One waste centre in south-east London had 2,300 nitrous oxide-related explosions just in 2025. Although this isn’t new, explosions are now bigger and more dangerous.
“A major concern is these larger items getting into incinerators where they explode,” said Hurren. “The smaller ones tend to get picked up in sorting more effectively, and their impact is relatively small – more of a pop than a bang in a non-scientific description.”
John Scanlon, chair of the Environmental Services Association, told the BBC that much larger canisters “become a ticking time bomb when they’re disposed of and find their way into our waste and recycling facilities”.
The paradox of prohibition strikes again
Despite the fact that use of nitrous oxide is falling overall, it is clear that the legislative changes to ban nitrous oxide have not decreased harms – and in fact, it may have increased the dangers and pushed consumers towards more risky behaviours. At the very least, noted Hurren, “to date, the legislation hasn’t shut down importing operations”.
To drug policy and harm reduction experts, the story of nitrous oxide is a familiar one: it is the story of a system that prioritises punishment and criminalisation at the expense of substantive policies that address the underlying causes of substance use.
“These consequences [of prohibition] were predicted by lots of experts in drug and alcohol policy,” Ryan noted.
TalkingDrugs put this to the Home Office. A spokesperson responded: “It is an offence to possess nitrous oxide with intention to wrongfully inhale it, and supplying it could lead to 14 years in prison. We will continue to work with partners across health, policing and wider public services to drive down drug use, and protect more young lives from such harms.”
