The New Zealand Chemical Industry Council says that if a proposed bill in the United States to ban the use and export of the poison 1080 succeeds, it will spell the end of all 1080 production.
A US lobby group is making a third attempt to get legislation passed that would ban 1080.
New Zealand is the largest user of the chemical in the world, and imports 90% of the production from the only US factory licensed to make it, Tull Chemicals of Alabama.
The Chemical Industry Council says if that production ceases, New Zealand organisations that use 1080 to control possums will be forced to find a new method.
However, the council does not believe the bill will succeed.
"Dark history in US" - lobby group
The head of the American lobby group says the poison has killed many non-target species there.
Predator Defense is lobbying politicians to support the bill and executive director Brooks Fahy says the use of 1080 in the US has a very dark history.
He says in the 1940s and 1950s it was spread through the American west from aircraft, much as happens now in New Zealand with helicopter drops.
But in the United States, Mr Fahy said the poison went through the food chain, killing birds of prey such as eagles and hawks, and endangered mammals.
He says a recent increase in the illegal use of 1080 is evidence of a growing black market in the US, where, as well as killing coyotes and other native species, it has also been responsible for the deaths of hundreds of dogs.
Mr Fahy also warns of a possible security risk if terrorist groups were to get hold of what he describes as the world's deadliest poison, with no known antidote.