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Indoor Air Quality


Indoor air quality refers to the condition of air within an enclosed workplace. The indoor environment of any building is based on several factors including location, climate, building design, construction techniques, building occupant load, and contaminants.

Four key elements are involved in the development of poor indoor air quality:

  • Multiple contaminant sources
  • Poor ventilation systems
  • Pollutant pathways
  • Building usage and occupant load

Outside sources for indoor air contaminants include pollen, dust, industrial pollutants, vehicle exhaust, and unsanitary debris near outdoor air intake vents. Other outdoor agents, such as underground storage tanks or landfills, may also affect indoor air quality.

Indoor contaminants are classified according to these categories:

  • Combustion products (e.g., smoke)
  • Volatile organic compounds (e.g., solvents and cleaning agents)
  • Respiratory particulates (e.g., dust, pollen, and asbestos)
  • Respiratory byproducts (e.g., carbon dioxide)
  • Microbial organisms (e.g., mold, mildew, fungi, and bacteria)
  • Radionuclides (e.g., radon)
  • Odors (e.g., perfume, smoke, mold, and mildew)

Additional examples of indoor contaminants include dust, dirt or microbial growth in ventilation systems, emissions from office equipment, and fumes or odors from any source.

Texas State University - San Marcos follows recognized guidelines for new building ventilation systems and air quality control; however, employees are also responsible for the quality of their indoor air. Because indoor air often contains a variety of contaminants at levels far below most exposure standards, it is difficult to link specific health problems with known pollutants. Employees must minimize all contaminants to reduce the low-level pollutant mixtures that commonly cause health problems.

The following practices will help ensure optimum indoor air quality:

  • Fix leaks and drips. (Moisture promotes microbial (i.e., mold and mildew growth.)
  • Clean mold and mildew growths with a bleach/water mixture to prevent regrowth.
  • Ensure that indoor ventilation filters are changed regularly.
  • Keep laboratory doors closed.
  • Minimize chemical and aerosol usage. Ventilate your area when chemical or aerosol usage is required. (These compounds include paint, cleaning agents, hairspray, perfume, etc.)
  • Do not block air ducts to control the temperature in your office.
  • Avoid smoking or cooking in enclosed areas. (This is strictly prohibited within University facilities and vehicles.)
  • If possible, open windows when it is cool and dry outside.

If you have any questions concerning indoor air quality, please contact the EHSRM at 245-3616.


Revised May 2011
Reviewed November 2014