You'll be wanting to check out the MSDS pdf linked to on the materials page.
It looks like the material is only bad for skin when it's molten. Other then that it seems fine.
(I realize the response is quite a bit late...but I just signed up for an account.)
I've heard about people having reactions to the stainless steel, but those people are apparently allergic to bronze. So long as you don't have such an allergy, that material should be fine."Hm, I'm so hungry I could eat an entire cow. Gerard, fire up the printer!"
A while ago I've designed a interchangeable and rotating ear tube for a friend of mine he didn't have any problems with stainless steel but he didn't wear it when sleeping and sometimes he wears other tubes.