A vote on mandatory palm oil labelling today could affect thousands of supermarket products.
The vote on whether to make labelling compulsory will be held at a meeting of the Australia New Zealand Ministerial Forum on Food Regulation in Brisbane.
The food and grocery industry is against such a move but health and environment groups say a change is urgent.
Dr Jenny Gray, head of Zoos Victoria, Australia, said palm oil was everywhere - from the pantry in the kitchen to the bathroom shelf.
Most consumers didn't know because the labels didn't specify the type of oil.
"Our estimate is that between 50 to 70 percent of products on supermarket shelves contain palm oil."
She said prominent health professionals, environment and nutrition groups had pushed for change for several years.
Dr Gray said UMR polling showed 92 per cent of New Zealanders and 84 per cent of Australians wanted mandatory labelling, and tens of thousands of people had signed petitions for change.
It was time the politicians made a decision, she said.
Environmentalists said the rapid expansion of palm oil plantations was destroying the habitats of endangered species like orangutans and tigers, and consumers needed to know.
Unmask Palm Oil founder Ben Dowdle has led the campaign in New Zealand.
"We want consumers to be able to choose what products they buy. At the moment labelling is generic and scientific, which means that a consumer wanting to buy certifiable palm oil or make a health-based decision for a certain type of vegetable oil simply can't do that."
Some major supermarkets chains including Foodstuffs used 100 percent sustainable palm oil in their home brand products and encouraged suppliers to voluntarily declare if they used palm oil, he said.
"We have a really messy mix of voluntary and generic labelling ... it just isn't working."
The Food and Grocery Council does not support mandatory labelling. It said because of limited space on a grocery pack, governments generally reserved mandatory labelling for issues of consumer health or safety.
Consumer NZ chief executive Sue Chetwin did not accept it would be too costly or difficult.
"They can change labels quite quickly when they want to."
Nutritionist and Auckland University of Technology lecturer Caryn Zinn said consumers should know what was in the products they used.
"Maybe the palm oil issue might raise that awareness about how processed everything is in our modern world."
Food Safety Minister Jo Goodhew, said mandatory labelling may not be agreed today, but ministers were considering a technical evaluation and would decide on the next step.
"If a decision is taken, New Zealand will disclose its position and how we voted," she said in a statement