Toxic fumes can infiltrate into or though a building from various sources---improperly stored chemicals, faulty refrigeration, equipment fires, gasoline engines operated near air intakes, etc.
If the presence of toxic fumes are suspected, the area or areas affected should be evacuated. Use a telephone away from this area and always call 9-911 if it is an emergency, or X-2200 (Physical Plant) if is not an emergency. If it is during business hours call X-2222 and have an university police officer notified.
Ventilate the contaminated area
It may be possible to clear an affected area by opening windows and/or activating exhaust fans, provided such action is undertaken by trained personnel.