Hopes the Government's latest crackdown on the misuse of nitrous oxide gets the message through to retailers. 

People inhaling the gas to get high - is becoming a serious public health concern.

Imports of the gas will soon need approval from the Director-General of Health - while large canisters, also known as nangs, will automatically be classified as psychoactive substances.

Retail NZ Chief Executive Carolyn Young told Ryan Bridge the canisters can be used for whipping cream, but it's not really a big seller for retailers.

She says they will never sell that many, with caterers preferring a wholesaler than a convenience store.