Molds make tiny spores to reproduce. Mold spores pass through the indoor and outdoor air continually. When mold spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on in order to survive. There are molds that can grow on wood, paper, carpet, and foods. When excessive moisture or water accumulates indoors, mold growth will often occur, particularly if the moisture problem remains undiscovered or un-addressed. So remember: the key to mold control is moisture control.


  1. Potential health effects and symptoms associated with mold exposures include allergic reactions, asthma and other respiratory complaints.
  2. There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.
  3. If mold is a problem in your home or school, you must clean up the mold and eliminate sources of moisture.
  4. Fix the source of the water problem or leak to prevent mold growth.
  5. Reduce indoor humidity (to 30-60%) to decrease mold growth by:
    • Venting bathrooms, dryers and other moisture-generating sources to the outside
    • Using air conditioners and de-humidifiers
    • Increasing ventilation
    • Using exhaust fans whenever cooking, dishwashing and cleaning
  6. Clean and dry any damp or wet building materials and furnishings within 24-48 hours to prevent mold growth.
  7. Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced.
  8. Prevent condensation: Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof, or floors) by adding insulation.
  9. In areas where there is a perpetual moisture problem, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation).
  10. Molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present. There are molds that can grow on wood, paper, carpet, and foods.

Information provided by EPA.