We have an ammonium mylar printing machine in the room next to my office. It is used to print reproducible mylars of record drawings. I had to leave the building as my eyes watered and my lungs felt like they were burning. Concentrations in an enclosed, poorly-ventilated space can reach 100 ppmv or more. This OSHA STEL for ammonia may not be sufficiently protective of workers since studies of individuals using blueprint machines indicate that concentrations in the range of 20-25 ppmv for brief periods can cause symptoms.
Ammonia is highly soluble in water and therefore in tissue fluids.
Because of its high irritation potential, most individuals quickly remove themselves from areas where ammonia is present. OSHA and your state occupational safety and health agency regulate ammonia exposures but do not regulate ammonia-generating sources. Exposures above this are in violation of OSHA rules. OSHA, however, can only regulate exposures in general industry and in the construction industry. They probably don't have jurisdiction in office buildings.