It's mentioned repetitiously in the 'Phalaris=the way of the future' thread, and is cited as being confirmed on the Merck index, as such. It's also in several of the other phalaris threads (I think first mentioned by Trickster (?) But I can't find the thread). As far as vendors go, it's just about any on-line vendor, that I could find, will confirm this, as part of the product description, along with some other basic data.

I think some of the people who had formerly participated in this thread, already knew this. Endlesness and Nen, at least (Nen had already posted a link for the thread I mentioned - I was just hinting that maybe people should read it, with my previous post)

Edit: Obviously, Benz knew this, as well.