Police warning to traders of law change on 'legal highs'

The substances, which give the user a so-called "high", were previously legally sold in some shops. But from December 23, 2009, it became an offence to sell the substances, which are classified as Class B and C drugs.

They include GBL (gamma-butyrolactone) and its associate chemical 1,4-butanediol (1,4 BD), a colourless oily liquid, the effects of which can be deadly especially when taken alongside alcohol.

Chief Insp Mark Allsop of Calderdale Police, said: "Some shops may still have stocks of these drugs and be unaware that they are now classed as controlled drugs. We will be making it clear in no uncertain terms that they must stop selling them immediately.

"The sale of these products is now a criminal offence. This also includes possessing such substances with intent to supply, being concerned in their supply or offering to supply them."

Police will be out in Halifax warning shopkeepers of the responsibilities under the Misuse of Drugs Act, 1971.

Police in Calderdale are also warning against the use of legal substance mephedrone (M-Cat), which is known as Meow, and is plant food.

Chief Insp Allsop said: "Just because something is sold legally it doesn't mean it is safe."

M-Cat has severe side effects and users have been extremely violent and displayed signs of mental instability, he said.

He added: "Other side effects include nose bleeds, anxiety, paranoia and over stimulation of the heart and nervous system. This is a dangerous substance and one that is not intended to be ingested into the human body.

"The effects are very dangerous and I would urge people to completely avoid it as it can have serious health implications for those who take it.

"We do not want to have to tell parents that their son or daughter has died or is seriously ill because of taking these substances."

The director of public health for NHS Calderdale, Dr Graham Wardman, said: "We would like to reinforce the warning from the police that these are dangerous substances. The effects of drug use can be devastating to those involved and their families."