Unconsciousness, heart attacks and death are among the potential consequences of a drug problem which has become too common among Murraylands teenagers.
Nitrous oxide canisters are sold legally in stores for use in whipping cream and inflating balloons, and known variously as nangs, nossies, whippets, bulbs, laughing gas and by other terms.
The same gas is used as an anaesthetic during dental work and childbirth.
When inhaled, it produces a short burst of euphoria or giddiness, according to the Alcohol and Drug Foundation.
However, it can also produce symptoms ranging from the mild - sweating, dizziness, blurred vision or weakness - to unconsciousness, heart attacks or sudden death.
Because the gas is frozen and pressurised, misuse also causes frostbite in the mouth and throat, and can burst users' lungs.
The long-term effects of exposure may include memory loss, loss of control of the bowels, spasms, numbness, ringing in the ears, depression or psychosis.
There is no safe level of nitrous oxide use.
Murray Bridge Councillor Karen Eckermann said several parents had approached her about the problem.
"These are being sold by supermarkets, to underage kids, under absolutely no supervision and without question," she said.
"It is a real and present danger here in the Murraylands.
"I know these nangs are not illegal as such, but it is a very dangerous practice and it won't be long before something serious arises."
Users come from all walks of life, Superintendent says
SA Police Superintendent James Blandford said the problem was not widespread, but it was present and had been for years.
Teenagers would always take risks, he said, but drug use could not be considered normal behaviour.
"You're basically putting a loaded gun to your head, just like when you take ice, fantasy or ekkies - you're dicing with your life," he said.
"I don't understand, in 2019, why life is seen to be so bad and hard that someone needs to take an illicit substance to get through a normal day or have fun at a party.
"Why is the fact that you've got friends, you're at a concert, you're at a party, not good enough for you?
"That's a question for our families and the generation today to have a conversation about: the basic values of life.
"We're not (just) talking about disadvantaged people, people who've had trauma and hit rock bottom; we're talking about normal kids in good homes who go to good schools."
As well as the physical harm they could suffer - Superintendent Blandford was aware of a case in Queensland where a boy became disoriented and fell to his death - users also risked addiction to more dangerous substances, he said.
"Unfortunately it's an open door to needing substances to get through life, and leads to cannabis, meth and all the noxious drugs that are out there," he said.
While sale, purchase and possession of the canisters was legal, he said, someone who sold or bought it for the purpose of misusing it could be fined up to $10,000 or imprisoned for two years.
Police also had the power to seize nitrous oxide canisters.
He encouraged retailers to consider their business practices and responsibilities.