EPA infographic: moisture control: Mold: The Key to Mold Control Is Moisture Control

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Core Message

The Key to Mold Control is Moisture Control

Mold will not grow without moisture. By controlling moisture in your home or building, you can prevent mold growth before it starts.

Three Steps to Prevent Mold

Step 1: Reduce Humidity

• Use exhaust fans in bathrooms and kitchens
• Run air conditioning during humid months
• Use a dehumidifier in damp areas (basements, crawlspaces)
• Keep indoor humidity below 60% (ideally 30–50%)

Step 2: Prevent Condensation

• Reduce indoor humidity
• Increase ventilation in problem areas
• Raise air temperature in cold spots where condensation forms
• Insulate cold pipes, windows, and exterior walls to prevent condensation

Step 3: Dry Wet Surfaces Within 24–48 Hours

• After any water intrusion (leaks, spills, flooding), dry all wet materials within 24–48 hours
• This window is critical — mold can begin growing within 24–48 hours on wet organic materials
• Use fans, dehumidifiers, and increased air circulation to speed drying
• Remove and discard materials that cannot be fully dried

If Mold Already Grows: What To Do

1. Fix the water source first — mold will return if the moisture problem is not resolved
2. Clean hard surfaces with water and detergent; dry completely
3. Replace absorbent/porous materials that cannot be cleaned:

• Ceiling tiles
• Carpet and carpet padding
• Upholstered furniture

1. Consult a medical professional if you or family members are experiencing symptoms potentially related to mold exposure

Key Facts

• Mold can grow on virtually any organic material as long as moisture and oxygen are present
• There are no EPA or federal standards for acceptable mold levels indoors
• The most effective approach is prevention through moisture control
• When in doubt about large mold problems (>10 sq ft), consult a professional

More Information

EPA Mold Resources: www.epa.gov/mold

A Brief Guide to Mold, Moisture, and Your Home: EPA 402-K-02-003