The Government is expected to announce a new regime for party pills and fake cannabis which will require makers to prove their products are safe before they can be put on the market.
Associate Health Minister Peter Dunne is due to announce the new measure today - a change to the current law under which such untested products can be sold unless proven to be harmful, as happened with Kronic.
The change was recommended by a 2011 Law Commission report on the Misuse of Drugs Act.
At the time Mr Dunne said the change would take some time because it was a complex area and set up temporary 12-month bans on substances for which the health risks were unknown. That resulted in about 50 synthetic cannabis products being taken off the market - as well as some weight loss and sports performance supplements.
Yesterday Labour drugs spokesman Iain Lees-Galloway welcomed the change, but hoped it was just the start of a complete overhaul of the Misuse of Drugs Act 1975 as the Law Commission had proposed.
"We think it's ridiculous that we've basically been experimenting on our kids by allowing the substances to come on the shelf and then trying to constantly chase our tails trying to get them off the shelf again."
Green Party drugs spokesman Kevin Hague said he supported the shift in principle, but the safety standards should not be unrealistically rigorous.
"It will be important to establish a reasonable standard of safety which accepts that there may be harms associated with consuming a particular product, but that adults should be free to make a decision to consume them," Mr Hague said.
If it was so strict that it amounted to effective prohibition, it could push party pills users toward harder, more dangerous drugs, he said.
He also believed that party pill makers could find ways to sidestep the new standards unless it covered all products made for human consumption.
"The industry has proved very adaptable and will attempt to define their products outside of the new provisions."
A total of 28 substances are currently on the temporary banned list, which was added to as recently as last week with a further four ingredients.
Mr Dunne said the bans would be rolled over as they expired to ensure there was no window for such drugs to go back on the market before permanent legislation took effect. The first lot is due for renewal next month.
Makers of the drugs said the temporary bans were futile because new products could be on the shelves for a while before the authorities noticed them.
- APNZBy Kate Shuttleworth @K8Shuttleworth Email Kate