There's a good website that seems to have straight info - it's www.ki4u.com. Shane, the owner, is a stand-up guy. His website discusses the differences in depth between pot. iodide and pot. iodate.<br><br>I have bought several bottles of Rad-Block from KI4U after doing a lot of research and reading about Shane's business in a Washington Post article around Dec. 28, 2001. <br><br>Good luck!<br><br>Mamabear<br>