It probably will- iodine is pretty corrosive/reactive. I figure it should chew Brad's pic pen up pretty well (at least I don't think they are a flouroethalyne based plastic), and those caps aren't air tight. Trust me, I chew on my pens and even a new one can have air sucked thought it.<br><br>Doug talks about the joys of finding things it doesn't react with at http://www.equipped.org/parepack.htm<br><br>Blueline stocks them if you want to order them from him. I got mine from the VetTech department at my old college.