I did not intend my post about why I chose the keeper over the other cups out there made of silicone to cause a ruckus.  All I did to find the information on silicone was to google 'where does silicone come from?'.  I knew it was polymer based on silica, but I didn't know how it was made or what if any health risks are associated with it.  The information I was referring to had to do with breast implants and other silicone prosthetic items that are inserted into the body and how when pieces break off they become lodged in the body and are many times not removable even with surgery.  Maybe I'm too careful, but that is just who I am.  We get enough toxins in our bodies from just going outside and breathing the air.

I'm not too worried about becoming allergic to the keeper, as most people with latex/rubber allergies actually develop them as children via the use of latex in the health fields though much of that is being fazed out.  Latex and rubber are renewable resources too for those who are environmentally conscious enough to buy and use a menstrual cup in the first place.

I personally would like to leave as small a footprint as possible when I'm gone, so even that 'little silicone cup' as another poster wrote would bother me.

Good luck with whatever you choose.  I'm having to use tampons while I wait for my new keeper to be delivered and they suck (even the natural fiber non-bleached ones I chose) not comfortable and don't last all day at work.