June 24, 2021

I, Science

The science magazine of Imperial College

Glue and aerosols have been popular routes to getting 'high' in the past, and now laughing gas is the latest volatile substance to be abused ...


Last month, nitrous oxide (also known as ‘laughing gas’, or for some reason, ‘hippy crack’) emerged as the second most popular drug amongst young people in the UK, behind only cannabis, with 6.1% of people aged 16-24 admitting to having taken it in the last year. Taking nitrous oxide recreationally is a form of volatile substance abuse (VSA) – deliberately inhaling the fumes of a substance which evaporates at room temperature to achieve a change in mental state. VSA has effects ranging from dizziness to euphoria, and even hallucinations. Of the thousands of products which can be used for VSA, nitrous oxide is probably the most glamorous as it’s cheap, legal, and you take it using brightly coloured balloons.

So perhaps it’s of little wonder that ‘hippy crack’ has captured the attention of the media. But nitrous oxide use is only a small part of a much murkier world. VSA carries high death rates and on average, 54 people die every year, with butane (a chemical in aerosols) responsible for 39 of those. To put that into context, in 2011 there were 103 deaths from heroin or morphine, 17 from cocaine, and 6 from cannabis, where each drug was directly implicated in death through its use alone.

Why, then, does VSA cause so many deaths? After fumes are inhaled, chemicals enter the bloodstream and quickly cross the blood-brain barrier before travelling to other organs, where they act as depressants and slow down the nervous system. The ‘high’ they create lasts only a few minutes, before the substance is rapidly broken down and excreted from the body. In most cases, that’s it. To date, there is no published evidence that butane inhalation has any long-term damaging effects. In the short term, however, the story is very different. As can be seen on the backs of many household products, ‘SOLVENT ABUSE CAN KILL INSTANTLY’.

“The crucial difference between VSA and other forms of drug misuse is the lack of morbidity,” said Dr John Ramsey, an analytical toxicologist at St. George’s University, “but as no chronic toxicity is associated with butane, the only visible long-term health consequence of using is death.” So VSA is like Russian Roulette – you either get high and suffer no long-term physical effects, or you die.

The majority of deaths from VSA are caused by cardiac arrhythmia, an irregular beating of the heart. This is caused by compounds in the vapour that sensitise the heart muscle to adrenaline, so any subsequent adrenaline release such as from a sudden fright or a burst of exercise can cause massive arrhythmia, which can be fatal in seconds. Death of this kind is known as Sudden Sniffing Death Syndrome, or ‘SSDS’. Importantly, SSDS is unpredictable and unpreventable, meaning there is a risk of it happening during any session of VSA, including the first, and there is no way of protecting against that risk. Other modes of death from VSA include chocking on vomit and asphyxiation, which can occur when any inhaled gas displaces enough oxygen from the lungs, but is more likely when solvents are inhaled using a bag.

Thankfully, in the UK today VSA is much less of a problem than it was 25 years ago. In the late 1980’s there was a glue sniffing epidemic and in 1990, deaths reached a peak of 152. The organic solvent, toluene, was the substance of abuse and caused permanent damage to the brain, lung, liver and kidneys after long term exposure. Toluene has since been banned from readily available commercial glues, and the number of deaths per year has decreased as a consequence.

Worryingly, VSA is still widespread among children and killed more under-15s during 2000-2009 than all other illegal drugs combined. Globally, VSA is also the most common form of drug misuse amongst children living on the streets, ahead of alcohol, tobacco and cannabis. In the UK, however, there has been a gradual increase in the average age of VSA death, which now stands at 30, as well as an increase in the number of deaths amongst women. The reasons for such a shift are unclear, but it makes the problem trickier to deal with.

So what is the solution? Stephen Ream is Director of Re-Solv, the UK’s leading agency on VSA. “Education is the key to prevention with VSA,” he asserted, “Young people, professionals and retailers need to be educated about the risks and how to deal with the problem. Campaigns have been very successful in the past, but more needs to be done if we are to end volatile substance abuse.”


IMAGE: henri ismali, Flickr