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.
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