Police have warned parents about the increasing use of so-called laughing gas after finding evidence it is being widely used across Epping Forest.
Silver capsules used to store Nitrous Oxide, which is used as a propellant gas in the catering industry and a painkiller, have been recently found in streets, parks and other public areas Epping, Waltham Abbey and Loughton.
Police describe it as the “drug of choice” for teenagers as it is legal and cheap to buy.
Capsules have been found scattered in Traps Hill, Stonards Hill and Hemnall Street in Epping, Sun Street in Waltham Abbey and, most recently, at various locations in and around Roding Road, Loughton.
Inhaling gas can cause euphoria, but use has been blamed for a number of deaths caused by a lack of oxygen.
It is illegal to sell nitrous oxide to anyone under the age of 18, if you believe they intend to inhale it.
An email from Loughton Neighbourhood Watch said: "Loughton Neighbourhood Watch is asking parents to be alert to the use of Nitrous Oxide by teenagers, which is increasingly becoming the teen drug of choice because it is cheap to buy, can be purchased legitimately online and is medically undetectable.
"Parents should now be discussing the dangers with their children, who probably just see it as a bit of fun."