Australian Drug Foundation drug prevention expert Geoff Munro and Dr Chris Wilkins from Massey University in New Zealand, who have published a paper on synthetic drugs, said the New Zealand system was a very different approach to that taken by Australia.

In Australia, governments have banned specific new substances, or groups of substances, on the basis that they are unknown and likely to cause harm.

However, Munro said drug manufacturers could modify a banned synthetic chemical and produce a new one in order to sidestep the bans.

He said Australia and other jurisdictions should study how the NZ system was implemented.

“The key issue at the moment concerns the testing regime: it is not clear how ‘low-risk’ will be defined; nor is it clear whether manufacturers or the government could be liable for damages if they approve a drug for sale that is later found to cause harm,” he said.

“Another important issue is whether more people will start using the drugs when they are legal and whether young people will gain access to them.”

Other issues identified in the paper, which are yet to be addressed, include how the drugs will be packaged and labelled and how consumers will be warned of the possible side effects; the price these drugs will be sold for; and how much tax will be collected by the government and whether it will be calculated on the drug strength, or per dose or by weight.

“These new classes of drugs are posing significant challenges for governments across the world,” Munro said.

“It’s important that we observe the effects of the New Zealand approach and evaluate the new approach to dealing with illegal drugs.

“The choices we make now could have a big effect on the health and wellbeing of our citizens in the future.”