The director-general of health says there's mounting concern about vaping products around the world, as the government here considers banning flavouring and colouring of certain products.

Dr Ashley Bloomfield says the government had been preparing to introduce a bill on vape regulation, which would limit vape flavours to tobacco, menthol and mint.

The only role vaping had was to help people quit smoking, and the products should not be provided to children or young people, he says.

Ashley says evidence of the health impact vaping has is still emerging, so it was appropriate for the government to regulate.

"I think there's a high level of concern about vaping and we can see reports coming internationally. As part of the bill, one the things that have been looked at is this issue of flavouring and some colourings," he said.

"One thing I think we all agreed on is that we don't want vaping to be attractive to children and young people."