Spice, as it is known on the street and in school playgrounds, has already been banned by at least four European nations including the Netherlands, where smoking small amounts of cannabis is tolerated.

But in Britain it remains "under review", according to the Home Office.

Spice contains JWH-018, a synthetic psychoactive substance which gives what the Royal Society of Chemistry has described as a "marijuana-like high".

However, packets of the herbal mixture which bear names such as Spice Gold, Spice Tropical Synergy and Spice Yucatan Fire are being sold as harmless incense.

JWH-018, a cannabinoid receptor, was created by an American academic purely for research purposes in 1995.

Since then it has been manufactured outside official laboratories. Chemists believe large quantities are now being made in China.

Its popularity has soared in the last year.

Last month Christian Steup from THC Pharm, a German company that makes legal painkillers from cannabis, detected JWH-018 in several packets of Spice, according to the RSC's Chemistry World magazine.

He said the substance was four to five times more potent than tetrahydrocannabinol (THC), the main psychoactive substance in cannabis.

He told Chemistry World that JWH-018 was "fascinating because the chemical structure does not look at all like THC, but it produces the same effects".


http://www.telegraph.co.uk/news/newstopics/politics/lawandorder/4611523/Teens-in-Britain-getting-legally-high-on-synthetic-cannabis-banned-across-Europe.html