Any HVAC pro's out there?

[Gidney N Cloyd]

Every so often in the building I work in I suddenly start itching like I picked up some fleas-- mostly scalp and exposed skin. Other times my eyes are so irritated I can barely see. I do have some perfume allergies but the symptoms are a little different and this can happen when the building is almost empty.
Is there any sort of chemical product that is normally introduced to the vent system? Maybe something regularly applied during maintenance?

[sasquatch]

1. Sounds like your secondary air system is messed up

Talk to the buildings manager and find out where the secondary air pipes are and see if they're plugged up.