yes, you are right.. silicon is pretty non-irritanting.. but if someone does have a problem with it I still think it might be worth while checking this out..
Anyway, here is what MeLunas on their website conserning the material:

"..Because TPE is more practical and better to process than silicone. These properties help us to keep MeLuna moderate in pricing and easy to create even more variants of the product. Also TPE feels smooth, dry and not sticky - meaning it is an all different surface feel (haptics). Many products originally made from latex or silicones are now made of TPE. It is just not easy to recognise.
The MeLuna material is, among other things, also used for the teats on baby bottles. Regarding the high regulatory requirement for baby products in Germany, you can be assured you are purchasing top quality..."

As far as I am aware, most baby bottle teats are made from sillicone and I thought that this was pretty non-irritating and non-allergenic. Isn't it used in medical equipment for exactly that reason? Correct me if I'm wrong.