We put our used paraffin in large carboys (from diluents for FACSCANS) let it 
harden.  Our chemical safety office said to put in garbage once it hardens.

I would not want to use for candles, the polymers might make huge black smoke
signals, and all the chemical contaminants would be a tidge scary, and any
floaters of tissues left in wax, filtering would be time consuming.  

My vote is with Joe Saby, not use it for private domestic consumption, candles

Gayle Callis