More must be done to raise awareness of the dangerous effects of laughing gas, councils have warned.
The Local Government Association (LGA) said it was "deeply disturbed" that the drug - which can result in a loss of blood pressure, fainting and even heart attacks - is still viewed as a safe legal high.
The gas, which is inhaled by users in a balloon, has become a popular recreational drug and the LGA estimate it is used by almost half a million people across Britain.
The association said it was concerned the practice was being "glamorised" by internet clips showing children inhaling the gas.
More top news
Rapper turned businessman Jay Z is to announce his own music streaming service to rival Spotify tonight revamping his technology company
Stephen Fry has quit Instagram, telling fans he has been "hounded off" the social media site.
The Office star Martin Freeman has given his backing to Labour in the party's first party election broadcast in England.