Resources Minister Bryan Green yesterday confirmed necessary buffer zones could not be enforced at the Hobart port like at Bell Bay and Burnie, where Tasports is licensed to undertake fumigations on board ships.

"It will not be allowed here in Hobart, given the proximity of rental properties and the general public," Mr Green told Parliament.

The Bell Bay fumigation of Forestry Tasmania radiata pine bound for China is expected to take place early next month.

It will end in the release of up to 1.5tonnes of methyl bromide - an ozone depleting gas, highly toxic to animals and humans.

Tasports has said it is confident the fumigation would not put its employees, other port users or the public at risk because the poisonous gas breaks down quickly.

But Bass Greens MHA Kim Booth said Mr Green's "chilling admission" was reprehensible.

Mr Booth said the Bell Bay port lay under the Tamar Valley inversion layer, which acted as a trap for airborne pollutants.

"No matter which way the prevailing wind blows, there are people located downwind from the port," Mr Booth said.

"It raises serious questions about the government's duty of care to people who live outside the capital city. "

The Wilderness Society says the controversy was further evidence an industry restructure was needed.

Society spokesman Vica Bayley said the fumigation would be averted if the timber was processed before being exported.

"Any long-term deals to export whole pine logs to China must be put on ice," he said.

Mr Bayley said it was up to the state government to intervene.

A Forestry Tasmania spokeswoman said the radiata pine destined for export was low quality and unsuitable for the local sawmillers.

She said the decision to export was made to maintain employment for contractors.

"It is not uncommon for softwood to be exported from Tasmania although Forestry Tasmania has not done so for years.

"Final details for the shipment from Bell Bay to China have not been finalised."