At this stage they effectively are. Since a law change last year requiring legal high manufacturers and sellers to prove the products were safe, no one has applied for approval of their product. No products are being manufactured or distributed legally in New Zealand.
The man sometimes referred to as the "godfather of NZ legal highs", Matt Bowden, said this month he was developing a safe legal high to be ready for sale in two or three years. Associate Health Minister Peter Dunne said that timeline was "incredibly optimistic" and it would be three to five years at least before a testing regime robust enough to ensure legal highs were low-risk could be implemented.
Remember, legal highs cannot be tested on animals.
On a FAQ on its website, the New Zealand Drug Foundation answers the question "Can councils ban psychoactive products in their area through LAPPs?". The foundation says no, not really. "Psychoactive products will still be available for purchase through the internet, or from stores in the next area ... Overly restrictive LAPPs run the risk of forcing force people ... to go to the black market ... or buy illegal drugs".
Maybe, for the criminally inclined. But maybe, if the products that eventually make it to market really are "low-risk", there'll be no need for a ban anyway.