It seems fairly straight forward : don't drink paint. Pigments like cobalt blue or Naples yellow are toxic. Cadmium red is cancerous. Unless you buy something labelled for small children, quality watercolors have to comply with ASTM D Standards, which if I understand well, are more about lightfastness than toxicity. I'm fine with that. I avoid paint except on paper and on my brush.

I learned to use a water container I can close. My cat likes to drink anything but the water in her bowl (it's too fresh probably) and there's often kids running around in my house. That cover saves the day. I cover my water when I'm not painting. But then, like all artists, I'm prone to the great mixup of the tea cup and water container when I paint, and this is not good. I dipped my brush in my tea, ruining a perfectly good earl grey (hot), and I also noticed that droplets of paint could fall into the cup if it's too close to the water pot. It's not healthy at all! So I tried to remember what I knew in ergonomics (I did some user interface and software/game design back in the days) to trick my brain into not mixing up my cup and my pot. Simple solutions are not always the easiest to think out , and because it's not really an interesting problem to think about, it took me some time to solve the problem. First of all, it's easy to mix pots because when you paint, you'll look at the paper not the pots. Unless you paint the pots, of course. So it has to be a spatial solution, not a visual one. Here's what I did.

I chose a water pot much taller than the cup, so my first reflex is to deep in the taller one. It's an easier gesture. Better, but not enough. I was still sometimes hesitating between the 2 pots, which is a loss of time. Spatially, it wasn't enough.
I put a pink perler bead coaster under the water and a white lacey one under the mug. It might seem chichi, but it actually taught me to put each container always in the same place.
This done, I put the tea on the left side of my table and the water on the right side by my palette (I paint with the right hand). Then I taught myself to drink only with the left hand, to be more safe.

That's it. No more droplets in the mug, no more paint in my tea either. It's safer, please do it too! In the summer I just use a mason jar with a cover and a straw for drinking. When I paint outside I have a mug with a cover, too. Good luck dipping the brush in it.

I thought that I was very much no nonsense, but I actually saw friends dipping their brushes in beverages without paying attention. When being very concentrated on your painting you might not even realize you're doing it. Stay safe!

Don't drink paint.