Black mold growth occurs when mold spores travel through the air and land in a wet environment, according to the Centers for Disease Control and Prevention. Black mold requires constant moisture and usually flourishes on materials with low nitrogen and high cellulose content, such as fiberboard, gypsum board and paper.
Mold spores enter indoor environments through open doors and windows. They also attach themselves to people, animals, clothing, shoes and bags, according to the CDC. Sources of moisture that sometimes lead to black mold growth include water infiltration, excessive humidity, condensation, leaks and flooding. If indoor mold is found, it is important to address the moisture problem to stop its growth. The best way to clean mold from hard surfaces is to scrub it with soap and water, a commercial cleaner, or a bleach solution of 1 cup of bleach per 1 gallon of water.
One way to prevent mold growth inside homes and buildings is to keep the humidity level less than 50 percent, states the CDC. Using a dehumidifier or an air conditioner when humidity is high can achieve this. Ensuring appropriate ventilation in the home, including exhaust fans in bathrooms and kitchens, is also important in preventing mold growth.