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Indoor Environment: Preventing Indoor Mold Growth

Learn how to recognize and correct moisture problems to prevent indoor mold growth.

Controlling moisture and humidity is key to indoor mold growth prevention. As long as moisture and oxygen are present, molds can grow on any organic material, including food, wood, paper, carpet, walls, ceilings, and insulation.

Control indoor moisture.

Prevent indoor mold growth by controlling indoor moisture:

  • Watch for condensation and wet spots on walls, ceilings, and floors.
  • Maintain relatively low indoor humidity.
    • Increase ventilation to decrease humidity and reduce condensation. Dehumidifiers and insulation can help moderate indoor humidity.
    • Vent moisture-producing rooms and equipment to the outdoors (e.g., showers and laundry facilities).
      • Use air conditioners or dehumidifiers when needed.
      • Switch on the ventilation fan when taking a shower.
    • Researchers, environmental rooms are engineered to control temperature and humidity levels. Because they are designed with limited or no mechanical ventilation, it's important to practice good housekeeping to prevent mold and mildew growth.
  • Make sure outdoor irrigation and rain water drains away from foundations to protect ground floors and below-grade rooms from dampness or water intrusion. Slope the ground away from the foundation and install drainage, as needed.
  • Stop leaks and address water intrusion promptly.
    • Dry or remove water-damaged materials within 48 hours to prevent mold formation.

Report water damage or mold formation immediately.

Report leaks and ventilation problems immediately to the appropriate location. 

  • Campus and SIO facilities: Facilities Management Customer Relations Service Referral Desk, (858) 534-2930
  • Hillcrest Medical Center: Facilities Engineering Help Desk, (619) 543-6454
  • Student Housing: Housing Maintenance, (858) 534-2600
  • Thornton Hospital: Facilities Engineering Help Desk, (858) 657-6400
Questions? Contact EH&S Occupational Health & Hygiene Services at