The HSE is warning about the use of laughing gas among young people.
The health body said it has become aware of reports of laughing gas or nitrous oxide use among young people and in particular 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 via a balloon.
To consume it, people open the cannister, which is easily bought legally online, transfer the gas into a balloon and inhale the balloon.
"We are aware that nitrous oxide can be bought online from a number of different websites," 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 popularly considered harmless.
"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," added the spokesperson.
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 shops.
The Dutch government has announced plans to include laughing gas on its blacklist of forbidden drugs.
But authorities became concerned when laughing gas started cropping up on street corners in the past three years.
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Unpublished preliminary data from more than 1,000 respondents indicates its use is emerging as an issue among Irish festival-goers.
According to Irish legislation, it is illegal to sell this substance for human consumption. It is also illegal to consume it under the Criminal Justice (Psychoactive Substances) Act 2010.
Due to its use in the catering industry, the gas can be purchased in large quantities online with relative ease.
The HSE plans to include information regarding the associated risks and how to reduce the harms as part of the festival campaign work in 2020.