I know many people say that sand is ok for juvie and adult beardies, but there is still a risk of impaction. Even if a separate feeding container is used, beardies lick things. Every inch of my room has been licked (not in an attempt to be eaten, but out of curiosity) by my beardie. He licks his basking rock and his tiles too. I could easily see him injesting sand, which causes impaction of the intestines which can be fatal, especially to younger beardies whose digestive systems are not as strong as adults'.
Sand also harbors bacteria and is very hard to clean. In general, loose substrates are dangerous for beardies.
I highly reccommend tiles as substrate. If one tile is defecated on, you can take it out, rinse it, and replace it. It's that easy. You will also have to disinfect them every month or so. Tiles also wear down beardie nails so you don't have to trim them. I use tiles and I love them. If you go to a hardware store, they may give you a few free tiles if you ask.
I have also heard great things about reptile carpet, astroturf, and shelf liner.
