The state government is taking a "zero-tolerance approach" to illegal vaping, announcing it has seized more than $1 million worth of illegal e-cigarettes and liquids this year. 

NSW Chief Health Officer Kerry Chant said retailers selling illegal vapes containing nicotine were being put on notice. 

She said young people believed vapes were just "flavoured water", but in reality, they contained poisonous chemicals which could cause life-threatening injuries. 

"[NSW Health is] cracking down on the illegal sale of nicotine e-cigarettes and liquids and taking a zero-tolerance approach to those who sell them," Dr Chant said.