There is no explanatory text or "alt" text (I know it's not an image as such). The accessibility recommendations for Font Awesome seem to recommend containing such text within a <span> and then using css to hide it (http://fontawesome.io/accessibility). This doesn't seem to have been done.
We have had complaints from users using screen readers who are having serious problems because of this.
I haven't checked, but I imagine this also applies to the "gear menus" in other places.