Young people and festival-goers are being warned about the potentially catastrophic effects on the body of inhaling laughing gas.
Leaders at the Royal College of Nursing (RCN) said a new public awareness campaign should be introduced to spell out the risks from nitrous oxide - which has been involved in the deaths of 36 people since 2001 in England and Wales.
Deaths doubled between 2015 and 2016 from four to eight and it is the second most popular drug among 16 to 24-year-olds.
The law was changed three years ago to make it illegal to supply or sell nitrous oxide for its psychoactive effect, but nurses say the law is not working.
Nitrous oxide, which can also be called Noz, hippie crack, chargers or balloons, is legally used by medics for pain relief and sold for the production of whipped cream.
It comes in small silver canisters and is often transferred to a balloon to be inhaled due to the risk of death from inhaling direct from the canister.
Its effects include feeling relaxed, euphoric and having fits of laughter, but it can also cause headaches, paranoia, nerve damage and sudden unconsciousness.
Stuart McKenzie, a clinical nurse manager at NHS Ayrshire and Arran and also from the RCN's mental health forum, said there was a lack of awareness of the dangers of the gas.
He said: "I think the prevalence of people using it is far greater than anyone would suspect.
"Parents of teenagers might also know about cannabis and legal highs, but if you asked them about the dangers of nitrous oxide, how many of them could confidently say what they were?"
'Like Ecstasy used to be'
Another member of the forum said nitrous oxide was considered a "soft drug" by some, adding: "There is a naivety about it.
"It's very much like Ecstasy used to be.
"It was only when we began to hear lots of deaths from Ecstasy due to bad batches and so on that people began to understand the dangers of taking it."
The RCN's professional lead for mental health nursing Catherine Gamble added: "It might give a short-term high but the long-term damage is no laughing matter.
"Along with the physical effects on the body, which themselves can be very serious, there are the psychological impacts associated with the abuse of any substance which can lead to addiction.
"The law is very clearly not working. Better public information, especially aimed at festival-goers and young people, about the risks would help people stay safe and reduce the burden on nursing professionals."
Unable to walk
In 2017, the Home Office said it would continue to prosecute those who sell nitrous oxide after two failed court cases.
In a subsequent review, the Home Office said the main aims of the Psychoactive Substances Act 2016 had been achieved, with the open sale of such substances largely eliminated and a reduction in health-related harms.
The Crime Survey for England and Wales 2017/18 puts the prevalence of nitrous oxide use at 2.3% for adults aged 16 to 59 (around 725,000 people), similar to surveys in 2016/17 and 2013/14.
The highest use in 2017/18 was among 16 to 24-year-olds (8.8%, or around 521,000 young people), also similar to previous surveys.
Last year, Olivia Golding, 24, from Bristol, told how she was left unable to walk or look after her son after consuming up to 15 balloons a weekend.
Roz Gittins, director of pharmacy at the charity Addaction, said: "When taken recreationally, nitrous oxide can cause euphoria and help people to feel more relaxed, sometimes becoming giggly or hallucinating.
"There are, however, risks associated with its use and breathing problems may occur when large amounts of the gas is inhaled over a short amount of time or in an enclosed space if the person cannot breathe in enough oxygen.
"It may also cause burns due to coldness if inhaled directly from a canister."
Matt Blow, policy manager at Young Minds, said: "Young people may experiment with nitrous oxide for all kinds of different reasons - to try something new, to do something they think will be fun, to fit in with a group, or to help them cope with difficult experiences and emotions.
"While experimentation is a normal part of life for young people, it's vital that everyone understands the potential risks of substances like nitrous oxide."