Toothpaste problem

Hi all! I'm having a weird problem that I'd love some advice for. The answer is probably staring me in the face, but I don't see it. I have five kids. Oldest is 8, youngest is 4 months. We have one upstairs bathroom in our house. During the day my 4 and 2 year olds go up and down the stairs and the 4 year old uses the bathroom with no assistance. The problem is that I THINK someone is eating the kids toothpaste. We seem to go through it kinda quick (not surprising) and the tube often looks more mangled than I'd expect. I want the toothpaste to be accessible for the older two who brush independently so I don't want to put it away entirely, but obviously I can't have kids eating toothpaste (it's all fluoride-free). Any solutions? I thought about pre-pasting their brushes for them the night before so I can just hide the paste. Or... having everyone brush in the kitchen only. But I not sure about either of these...anyone? Thanks! via /r/Parenting http://ift.tt/2i1mYop