The HSE has warned young people about the dangers of using laughing gas, saying it can lead to death by suffocation.
The executive said it has become aware of anecdotal reports of the use of laughing gas, or nitrous oxide, among young people, particularly among festival-goers.
The gas is intended for use as an anaesthetic in dental practices or as propellant in whipped-cream canisters.
Nitrous oxide is a colourless gas that people inhale, usually from a balloon. To consume it, people open the cannister, which is easily bought legally online, transfer the gas into a balloon and inhale from it.
"We are aware that nitrous oxide can be bought online from a number of different websites. Costs will vary, with some sites selling boxes of cartridges for €8 to €10 up to €30 or €40, depending on the quantity and product," said a HSE spokesperson.
As with many other substances, the quality and purity of nitrous oxide depends on the source.
When inhaled, the drug creates a short-lasting euphoria.
However, the HSE spokesperson said: "There are a number of risks associated with use, it is known that death from suffocation or lack of oxygen can occur. Nitrous oxide can displace the air in the lungs and can temporarily prevent oxygen from entering the bloodstream.
"Long-term risks associated with frequent use can lead to red blood cell problems and Vitamin B deficiency."
Irish tourists may have come in contact with nitrous oxide while on holidays in Europe or Asia.
In the Netherlands, laughing gas has been available in nightclubs as balloons filled from large canisters or as small canisters available from head shops.
In response to a rapid increase in the use of nitrous oxide among young people, the Dutch government plans to include laughing gas on its blacklist of forbidden drugs.
Last summer, the HSE launched an online survey in partnership with Trinity College Dublin to gather data on drug trends and harm reduction among Irish festival attendees.
Unpublished preliminary data from more than 1,000 respondents indicates that nitrous oxide use is emerging as an issue among Irish festival-goers.
Under Irish legislation, it is illegal to sell it for human consumption and to consume it.
However due to its use in the catering industry, the gas can be purchased in large quantities online with relative ease.