A national ban on retailers selling vapes should be urgently brought in to curb easy access to illicit products containing nicotine, the NSW premier says.

The state government on Monday committed $6.8 million over three years for enforcement of vaping restrictions and services to help young people quit using the products.

Premier Chris Minns said more inspectors checking for outlaw vape-sellers would help but a national approach was needed as states waited for planned border controls to be introduced.

Under existing Australian laws, vaping products containing nicotine can only be bought and sold with a prescription but non-nicotine products are available over the counter.

Many of those products have also been found to contain nicotine and other harmful chemicals.

"If it's on every street corner, it's very easy for young people to get access to e-cigarettes that have high concentrations of nicotine," Mr Minns said.

"If it was banned across the country, in other words you couldn't sell e-cigarettes in a retail setting, it would be a lot easier for us to have a compliance regime across the state.

"We've got to stop it at the border and the national rules have to change."

The federal government in May announced $234 million for tougher regulation, including stricter import and packaging controls.

The measures, which are yet to be introduced, include banning the import of non-prescription vapes for retail settings, and of single-use products.

Federal Health Minister Mark Butler said he aimed to have the ban in place before the end of the year as part of comprehensive measures supported by all states and territories.

"All governments ... are agreed on a plan, on a mission to get rid of these things that are changing the lives of our children for the worse, making school communities deeply worried," he said.

Separate research from the University of Wollongong, funded and commissioned by NSW Health, found more than 98 per cent of vapes seized from retailers and students at Sydney schools within a survey period contained high nicotine concentrations.

Most of the products did not list the addictive drug as an active ingredient, while a small share of the vapes contained other harmful substances such as ethylene glycol, a chemical compound found in anti-freeze.

Evidence showed vaping was a gateway to smoking in young people, with e-cigarette users three times more likely to progress to traditional cigarettes, according to health officials.

Nicotine could also cause changes to development in young people, including impaired learning abilities and memory.

NSW Health Minister Ryan Park said the clampdown was part of a focus on vapes that could also lead to increased penalties.

At present, retailers can be fined $2000 for illegal sales.

Mr Park said NSW was not going to wait for a national import ban to look at strengthening laws around vape seizures and inspections to crack down on rogue retailers, only a handful of which have been successfully prosecuted.

The state's education department is also considering installing 40,000 vape-detection devices in public schools by July.