Coffee : Enkore Coasters Set of 6 (Espresso) with Holder - Protect Your Furniture From Water Damage & Scratch - Good Grip, Deep Tray, Large 4.3 inch Size

Q: Can you use hot drinks

YES ! It is made from cilicon that has a very high melting point. I use it for hot drinks for more that a year and its as new ! Very high quality.

Q: Are these coasters bpa free?

Yes, they are because the silicone material is FDA grade which means they can be in contact with food although they are designed to be used as coasters Having said that, I would not recommend to use them as chew toys for kids.

Q: What is the thickness of these coasters?

1/4 inch thick, love these coasters my glasses and cups don't sweat and stick to these like they did with the cork type. Thinking about getting another set.

Q: What happens when these coasters puddle with a drink that's been sitting there for a long time? Does the liquid spill onto furniture?

I haven't measured them, but the coasters are probably a 16th of an inch recessed or deep below the dots. The Coasters retain liquid well, I believe the only way the liquid would get on your table was if you let it really overflow, or spilled it when removing it to empty it.