Types of White Mold

Updated February 21, 2017

Mold is a variety of fungus that decays organic matter. Thousands of mould spores are floating through the air inside and outside of your home. They can become a nuisance and can cause health problems if left to grow extensively inside your home or if you work in a mould-infested area. Some varieties of white mould are more harmful than others and grow for different reasons and in different places.


Aspergillus is a common variety of mould. Depending on the genus of the mould it can appear grey, brown, yellow, green, black or white. Aspergillus can cause an allergic reaction and hay fever-like symptoms. It can also cause long-term health concerns, such as lung infections and the spread of toxins through the body. Those with susceptible respiratory systems are particularly at danger of long-term effects. Aspergillus commonly grows in walls, insulation, soil and clothing. It grows most often in areas that are damp and poorly ventilated.


Penicillium is a common type of mould that was once used to discover the common antibiotic penicillin. This variety of mould is commonly found on food, such as older cheese or rotten fruit, and is not normally hazardous. The worst result of penicillium exposure is a mild allergic reaction. In most cases it is completely harmless. Cheese-makers often even encourage the growth of white mould on their fine cheeses. Nonetheless, those that are susceptible to respiratory difficulty--including the elderly, pregnant women, children or asthmatics--should avoid any mould consumption or discuss it with their doctor. In some cases, penicillium can grow on walls or insulation. The mould can appear blue, green or white.


Acremonium most often grows in damp places, such as basements, laundry rooms, bathrooms or attics. It can also grow in areas that are not well-ventilated. The mould can appear grey, brown or white. It often grows in insulation, drywall or Sheetrock. It can cause reactions ranging from a mild allergic reaction to severe lung infections, depending on the extent of the growth and a person's exposure to it.

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About the Author

Kaye Wagner has been working in the fields of journalism and public relations since 2006 and is a recipient of a National Hearst Award. She is particularly interested in home-and-garden projects, as well as beauty and fashion writing. An avid traveler, she also writes travel reviews and guides. Wagner earned a Bachelor of Arts in journalism from Brigham Young University.