try following the chain of command. If none of that works go to HR. Still having problems? Try and get some personnel from the asthma and allergy area to back you up. I work in sales and sometimes a customer will come into the store with a scent so strong that it lingers even after they have left the store. When that happens I duck to the back and ask a coworker to handle the customer. Good luck, I know how hard it can be