I put a 2000 flush tablet in my toilet tank, and did not consider the possible danger that could be for my cat. I don't think she does drink from there, but maybe she does when I'm not around. I will keep the lid closed at all times now, and hopefully I won't forget. The blue water will probably remind me to do so.
But what about the possible fumes that may create, should I be concerned?
do you close your cat in the bathroom? Even if you do, I doubt there would be any problems with fumes. If the door is open, I would think there would be enough air movement to prevent any problems, if there were actually any to worry about in the first place.