Schools are resorting to locking toilet blocks in an effort to curb the increasing numbers of students vaping.
One principal described vaping as an "epidemic" and another said they had seen a marked increase in the last six months.
Secondary Principals' Association of New Zealand president Vaughan Couillault said he had heard of schools, including his own, making particular toilet blocks key access only in a desperate bid to clamp down on the growing trend.
Aquinas College on the Gold Coast went a step further last month by deciding to lock all toilets during class time requiring students to get permission from a teacher to access the bathroom.
Couillault, principal of Papatoetoe High School, said schools were using all sorts of methods because vaping was becoming an increasing issue that more and more principals were addressing on a daily basis.
Because of that, he had made the decision to lock one set of boys toilets that seemed to be a favoured hang-out.
That meant students in classes near there had to ask their teacher for a key to access it.
"It's just around the back of the building and it's not an area that teachers naturally walk past so it's proven to be a bit of a hot spot so we are trying to cool it down," he said.
Couillault said vaping was a slightly more complicated issue than smoking, which was now almost non-existent.
In some cases vaping helped people stop smoking and there was still little research on the harms of it which made students more defensive of it as opposed to accepting it was not socially acceptable, he said.
He said staff at his school were dealing with an instance of vaping about once a week.
Auckland Secondary Principals' Association president Steve Hargreaves said he had not heard of schools locking toilets but could understand why desperate principals would resort to that.
"Vaping is a problem and it's growing," the Macleans College principal said.
"What's changed is that initially there was a buzz around it and it was about watermelon flavour and things that probably seemed quite exciting at the time. Now it's moved into students vaping nicotine and there's a hard core of students who really now are struggling to get through the day because they're vaping nicotine."
Hargreaves said he had to deal with the issue once every week or two and had stood down a boy for vaping this week. Another Auckland principal he had been speaking to stood down five students for it last week.
Macleans College stood students down the first time they were caught vaping, he said.
He said students often had the perception it was risk-free.
"It's definitely not risk-free. In fact, we don't know what the full consequences are going to be that will play out over time. It is scary because we could be setting our students up to deal with some serious long-term health issues."
Rangitoto College principal Patrick Gale agreed it was a growing problem and said he'd noticed a marked increase in the last six months.
"It is becoming more on-trend or fashionable among a certain group of students to be involved in this sort of behaviour," he said.
"New Zealand's done such a great job in terms of decreasing the levels of youth smoking that for vaping now to be suddenly very much in vogue is such a shame."
Gale said his school also had an instant stand-down policy for anyone caught vaping and had stood down a number of students this week.
As for locking toilet blocks, it was not something the school was considering.
"We're not going to be quite as draconian as locking toilet blocks. It is very much a minority who are involved in this behaviour so we don't want to punish everybody."
Auckland Grammar School headmaster Tim O'Connor said vaping had been a problem at his school for some years now and described it as an "epidemic" among the 13 to 15-year-old age group.
He said they were dealing with vaping-related issues daily and were about to install vape detectors.
"They can hide it. Some of them are odourless, some of them you can't see any form of smoke being emitted."
When students were caught they were sent straight to a deputy principal who called in their parents. Some students had been formally stood down for it.
O'Connor believed vaping was so popular among the younger age group because they were easily accessible, looked cool and came in a variety of sweet flavours.