Opposition health spokesman Walt Secord said NSW Labor is proposing the most comprehensive controls on e-cigarettes in Australia, amid alarm over the rapid growth in use of the devices, and the potential risk to children.

Public health groups are concerned that e-cigarettes are being displayed on shop counters in bright colours, often in the shape of lipsticks or pens, with fruit flavours.

Labor, if elected, would restrict the promotion and retail display of e-cigarettes to keep them out of sight, matching tobacco restrictions.

The Baird government has said it will ban the sale of e-cigarettes and e-liquids to minors. This includes the fruit flavours that don't contain nicotine, but are seen as a gateway to "vaping" – inhaling vapor containing small amounts of nicotine from electronic devices – for teenagers.

But Mr Secord said this would leave large loopholes.

"There is little to stop someone from 'vaping' on public transport or in a hospital. The Liberals and Nationals have only limited their sale to minors. The community expects a better response than that," he  said.

Labor would match the ban on sales to children, but also hold a public inquiry into e-cigarette use because "the jury is still out".

"There are two schools of thought: some researchers believe they are a gateway to cigarettes where other researchers believe they move smokers away from the habit," he said.

Labor believed a total ban was not realistic, but "vaping" needed to be properly regulated.

The Heart Foundation has called for e-cigarette regulation to match smoking bans for tobacco.

A Newspoll survey of NSW residents commissioned by the Heart Foundation over January and February found 80 per cent supported a ban on sales to children, and 70 per cent wanted restrictions on smoking in public spaces.

Health Minister Jillian Skinner has said the Baird government "is still considering options for a broader, evidence-based response to electronic cigarettes".

The Queensland government banned the use of e-cigarettes in non-smoking areas in January. The ACT is holding an inquiry into their use.

The sale of e-liquid containing nicotine is illegal in Australia, but it is believed internet sales of the products are booming.

An audit by NSW Health found 70 per cent of e-liquids sold in NSW shops contained nicotine, even though they weren't labelled as such.

Ingesting liquid nicotine was potentially lethal to children, and poisonings had climbed in Australia, according to NSW chief health officer Dr Kerry Chant.

Dr Chant wrote to retailers last month warning them of the health risk of e-cigarettes.

E-cigarettes are battery-powered vaporisers that heat liquid to produce a vapour that is inhaled to mimic smoking.