"It will also become illegal to possess these products, so anyone thinking of stocking up ... should bear that in mind."
The penalty for possessing a small amount of a psychoactive substance is a $500 fine.
Possessing a large amount with intention to supply is punishable by up to two years' jail or a fine of $500,000.
Retailers and manufacturers will not be compensated for their losses.
Officials estimate that the industry was making about $140 million a year.
The Ministry of Health warned that between 150 and 200 people had developed dependence on legal highs and would require withdrawal management.
The emergency law change will also stop tests on animals being used to seek approval for psychoactive products.
Mr Ryall clarified that the psychoactives testing regime would accept overseas animal drug trials which proved that a product was unsafe.
"No one will be doing animal testing to support an application here because it will not be able to be used for consideration."
Labour associate health spokesman Iain Lees-Galloway said Labour planned to support the bill.
But he blamed National for "making a hash" of implementing the new rules for psychoactives. National had last year opposed a Green Party proposal to ban animal testing, but later admitted that concerns about animal harm were holding up the much-needed testing regime. The Government's ban on animal testing was belated, Mr Lees-Galloway said.
The Green Party planned to abstain on the bill because it supported a ban on animal drug trials but believed the blanket ban on synthetics would create an untested black market.
Mr Ryall said the 41 products which had temporary waivers were not linked to adverse reactions when they were approved last year.
But since the bill passed in August, health authorities had reported an increase in serious reactions including vomiting, seizures and psychotic episodes.
The Green Party tabled an amendment to rule out animal testing in the Psychoactive Substances Act, not the Labour Party as reported in an article yesterday.
Synthetic cash
• 1kg of psychoactive substance costs $900-$1450.
• It is usually mixed with damiana leaf, a cheap imported herb, and packed into 2.5g packets.
• A kilogram of raw product makes about 10,000 packets, sold wholesale to retail outlets for $8-$12.
• The retailer sells the same packets for about $25 each.
• The original kilogram of active ingredient has gone from, at most, $1450 at import to $250,000 at retail.
Source: Legal high insider.
