Thousands of illegal vapes have been seized in Western Australia amid warnings a new generation is becoming addicted to nicotine.

More than 15,000 e-cigarettes, valued at more than $500,000, were confiscated from 32 retailers during a six-week WA Health crackdown.

Of the devices tested at Perth's ChemCentre, two thirds were found to contain nicotine, despite being otherwise labelled.

It is illegal in Australia to sell or purchase e-cigarettes containing nicotine unless they are obtained under a doctor's prescription.

WA chief pharmacist Meeghan Clay says disposable vapes are often targeted at children and misleadingly labelled as containing zero nicotine.

"I'm very concerned that most (users) are vaping on nicotine and becoming addicted, and that we're going to see a whole new generation of people addicted to nicotine," she told reporters on Friday.

"People importing these products and selling them are trying to avoid detection by not having them labelled as containing nicotine.

"When you buy a vape, you don't know what's in that vape."

About 3000 retailers have been reminded of restrictions on the sale of e-cigarettes as part of the health department's surveillance efforts.

While smoking rates have continued to decrease, there are concerns young people who have never lit up are turning to the devices.

One in five non-smokers aged 18 to 24 have tried e-cigarettes, according to the 2019 National Drug Strategy Household Survey.

"I think there's been a misapprehension in the community that vaping is less harmful than smoking," Health Minister Amber-Jade Sanderson said.

"Certainly that's being challenged now, and we want to be clear with parents: vaping is not safe."

The e-cigarettes were seized from vape stores, delis and pop-up kiosks. Ms Sanderson said penalties would be considered for the retailers.