Fire (Flame) Safety?

Hello – this site has been EXTREMELY wonderful! Have gotten many different answers to a question, and would like yours, too.
Project in question is a pillar candle base. Is there a fire hazard if a candle burns down to the resin base? What about the walls, as in a votive-type or cubed candle holder?

I could always cover the resin with clear glass on either the candle-side, but that kind of defeats the purpose of using resin!
Your thoughts on the safety of resin as a candle holder is appreciated. I don’t want to cause any hazards!
Thanks so much.
Karen Rosenberg