Around the country, high school students are rushing home after school, bursting through the door and heading straight to the bathroom.
Secondary schools are grappling with how to deal with vaping students commandeering bathrooms at break times and between classes.
Parents are worried their children feel too intimidated to use school bathrooms because older students are in there vaping.
One Wellington parent said her son holds on all day and, initially, she didn't understand why.
After seeing other parents' concerns on a school Facebook page, she discovered her son doesn't use the toilets because students are vaping in the cubicles.
"I put two and two together and realised, maybe that's why my son had a bladder infection. He won't use the toilets at school".
Another parent from the same Wellington school said her daughter in year nine can't get in the door.
"The bathrooms with doors have got people behind them vaping and those kids won't come out to let other kids use the toilet".
She said that makes it difficult for students who are dealing with their first periods at school.
"Twice so far this year, I've had a call from the school to pick up my daughter because she's sick. But it's actually been that she's become soiled because she can't access the bathrooms to clean herself up or get changed."
The school's principal admits bathrooms are used for vaping.
But he said only a small handful of students vape on campus and the school is working to stop them.
"We do not want students vaping on site. We do not accept that, that is not part of our school vision or values and we do take it really seriously in our kura".
The principal said his school has a system so teachers are clear about why students are outside the classroom during lesson time.
Teachers are also on duty during breaks, with specific instructions to monitor bathrooms.
Last term, as vaping in the school became a growing problem, he said the senior leadership team began checking hallways and bathrooms between classes.
"If a member of the senior leadership team were to walk into the bathroom, there's a student in a cubicle and there's a big puff of vape mist that rises from that cubicle, absolutely we will be talking about that students behaviour with that student".
The principal said a mixture of education about the health risks of vaping and disciplinary action will make a difference.
But he said the government could do more to stop teenagers accessing vape products and better support schools to help their students quit.
"Could the government regulate the packaging, regulate the marketing, regulate the hours vape stores can open, regulate the proximity to schools"?
Vape-Free Kids NZ spokesperson Charyl Robinson agrees.
She said parents across the country are seeking support for their children who vape.
But she said more and more parents are worried their children are too afraid to use school bathrooms because other students are in them vaping.
"Some are feeling intimidated at being offered vapes, some don't want to be accused of telling on kids, and there's the embarrassment aspect if you need to use the bathroom but its full of other kids vaping."
Robinson wants the government to take stronger measures to tackle youth vaping.
"Our teachers don't have capacity to be monitoring the toilet blocks, they don't have capacity to do the job the government ought to be doing.
"We need harder lines from top down. Government legislation, shut down, prosecution of uncompliant retailers. Just squeeze the market so that our kids are not finding it as easy to get their hands on these things."
Last month the government announced new restrictions to help crack down on youth vaping.
That included effectively banning disposable vapes and stopping new vape shops being set up within 300 metres of schools.
RNZ
