I worked in a place that had the deep As furnace right by the entrance.
One day I walked in and was hit by garlic smell, and I instantly evacuated the fab.
Turned out the furnace operator had pizza for lunch.
What fallout did I get? None. My direct supervisor and the plant manager totally supported me. Although both the operator and I were a bit embarrassed...
Better to be safe than sorry. I have been in several fabs where the AS furnace or implant etc was by the main entrance. Always seemed foolish to me.