If it’s this stuff, it is biocompatible. The composition is:
45 wt% SiO2, 24.5 wt% CaO, 24.5 wt% Na2O, and 6.0 wt% P2O5
It’s easy enough for HID to put transponders in glass, even if they don’t intend it for human implantation. In addition to being biocompatible it’s also chemically inert, so you can place it in a variety of resins and other potential reactive materials. Encasing it in glass also prevents any microscopic sparks in the electronics from igniting flammable gases.
This could also be intended for “asset tracking” cattle, or even in medical applications like embedded in a hip replacement pre-insertion