For the first time, guidance to help schools in Wales tackle vaping has been published - but what does it mean for you?
Head teachers have reported growing problems, including having to monitor toilets, increased exclusions, and disrupted lessons.
Figures from the School Health Research Network showed 20% of Year 7 to 11 students said they have tried vaping.
Public Health Wales said there are multiple solutions to these problems.
Dr Julie Bishop, director of health improvement at Public Health Wales (PHW), said education settings have experienced "significant new challenges" on vaping among young people.
It said heads have reported vaping use as a growing issue over the past two years.
Figures from the School Health Research Network, which surveys Welsh pupils, said 20% of Year 7s to 11s (broadly 11-16-year-olds) say they have tried vaping.
Some 5% of secondary school pupils said they vape at least once a week.
