The government has decided not to join the scheme because it would hamper British attempts to ban new drugs coming onto the UK market.
Home Office Minister Norman Baker said: "The coalition government is conducting a review into new psychoactive substances, and alongside our programme of work, we are looking at a range of options including legislative ones to enable us to deal with the dangers many of these substances present even more speedily and effectively."
Steve Brine, who has long campaigned over the issue, said; "This is a smart move in my view. One key part of our strategy to tackle this menace is the ability to move fast and ban new dangerous products before they can do harm. Sadly, European rules in this area do exactly the opposite so we have to sidestep the bureaucracy and protect people. Far from diminishing our ability to fight psychoactive substances this enhances it."