For the first time in almost 20 years a genetically modified organism has been approved for human medicinal use in New Zealand.

The Environmental Protection Authority's green-lighted an application that will see a GMO called Pexa-Vac used in a clinical trial for liver cancer treatment.

It's the first time since GM restrictive laws were passed in 1996 that a GMO has been approved for use as a human medicine.

Assurances are being made that an approval of a genetically modified organism for human medical use poses no threat.

Minister for the Environment Nick Smith said the EPA has taken the very best scientific advice around the risk to human health, as well as to the environment.

"Their work has shown that it is very unlikely to survive out side of the human body, there are very strict conditions about the way it will be administered. They're of the view that there is no risk to public help or to the environment."

The EPA's decision is being endorsed by the Government.