Mold risk in homes rises as indoor humidity exceeds safe levels

A recent guide warns that indoor humidity above 60% creates conditions for mold growth, especially in poorly ventilated areas such as behind wardrobes, under carpets and around windows. The U.S. Environmental Protection Agency recommends keeping relative humidity below 60%, ideally between 30% and 50%, while the Centers for Disease Control and Prevention advises a maximum of 50% during the day. Persistent high humidity can lead to mold even without visible stains, producing musty odors and potential health issues like nasal congestion, cough, eye irritation, skin rash and breathing difficulties, particularly for people with asthma, allergies or weakened immune systems.

To prevent mold, the guide suggests regularly measuring humidity with a hygrometer, increasing ventilation, using fans in bathrooms and kitchens, keeping furniture away from cold walls, and employing dehumidifiers. Leaking roofs or pipes should be repaired promptly, and wet materials must be dried quickly. Simple steps such as opening windows, airing out rooms and reducing indoor moisture sources can lower the risk of mold-related problems.