Odors
Start with the most logical odor source. If odors do not seem to be coming from the immediate area, use chemical smoke to track airflows from adjacent areas from which the odors may be emanating. Also, remember that your nose quickly becomes used to most odors. "Reset" your nose often with clean air to more effectively track odors with your nose.

Biological Sources

Excess moisture can cause mold, dust mites and bacteria to flourish. Moist or wet materials should be dried within 24-48 hours to avoid mold growth or replaced if mold already exists.

• Do you see or smell mold?
• Are there signs of rodents or pests?
• Are there animals or pets in classrooms?
• Is condensation often present on windows or cold surfaces?
• Do you see wet or frequently damp areas?
• Is indoor relative humidity above 60 percent?
  
  

Building Sources

• Has there been recent painting, roofing, remodeling or construction?
• Were there pesticides applied recently?
• Has new furniture, flooring or equipment been installed?
• Are solvents or other chemicals stored in poorly sealed containers?
• Are areas in the building overly dusty?
• Are combustion appliances used in rooms without adequate ventilation?
  
  

Housekeeping Sources

• Do complaints occur during or just after housekeeping activities?
• Are chemical or cleaning products used near the complaint area?
• Are any new cleaning products or procedures being used?
• Have there been recent changes in housekeeping procedures?
• Are housekeeping products sufficiently diluted or used based on manufacturers' directions?
• Are products stored in sealed containers and/or in rooms with adequate ventilation?
• Are paints, markers or other art supplies capped or closed?
  
  

Outdoor Sources

• Are sources of odors or pollutants (e.g., vehicle exhaust, stored chemicals or trash bins) located near outdoor air intakes, windows or doors?
• Are there sources nearby or upwind:
• Exhaust from traffic, loading docks or flues?
• Industrial, agricultural or lawn care activity?
• Construction activity?
• Are pollen levels high?