Idea of Biohazard Icon
It's a closed off circle, like a ring, with an almost flower like shape on top of it. This flower like shape is make of three almost closed off letter c's, which are incomplete circles, at different angles and anchored to the center of the ring beneath them with a single dot.
This page contains the Biohazard vector icon, as well as variations of this icon in different visual styles, and related icons. All icons are in the flat vector style, however, differ by the line thickness, fill, and corner radius.