What to Know About Chaetomium Mold

Mold is important in nature, but shouldn't be tolerated indoors. Molds like Chaetomium can cause serious health problems. Here's how to deal with it.

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Although each of the 100,000 known mold species are vital to their natural ecosystems, mold in your house is never a good thing. Not only does it demonstrate poor indoor air quality and excessive moisture, but some molds can be dangerous to human health, too. Learn about a group of molds called Chaetomium, how and why they grow, and how to eliminate them.

What Is Chaetomium Mold?

Chaetomium is a genus of dark-walled molds with 95 known species. Discovered by German zoology professor Gustav Kunze in 1817, these molds begin as white fuzzy growths that turn bluish-green as they reach maturity. The spores are dark brown in color and they’re shaped like a fat football. These spores spread in the air, but often don’t disperse unless mature mold is disturbed and shaken loose. Growing best in cellulose-rich environments, Chaetomium digests this cellulose as it matures, gradually decomposing the material and giving off a distinctly musty odor.

Where Is It Commonly Found?

Chaetomium species grow worldwide, most commonly in dung, damp soil and decomposing plants. Indoors, they attach to any moist surface containing cellulose such as wood, ceiling tiles and drywall. They’re especially common on water-damaged surfaces.

What Are the Health Risks?

This mold can cause serious health problems. Like many molds, it can easily lead to severe allergic reactions and respiratory infections in immune compromised people. Several species produce carcinogenic mycotoxins. Chaetomium is also known to cause skin and nail infections. In rare cases, fatal brain infections have been associated with Chaetomium.

How to Remove and Prevent Chaetomium

All mold discovered in homes should be eliminated right away, but Chaetomium carries greater urgency than most. As the second or third most dangerous mold genus to humans, dealing with an infestation quickly could make the difference between no health consequences and serious ones.

Protect yourself with a HEPA-rated respirator (and filter), gloves, eye protection and a disposable set of coveralls. As with all mold, the first step is eliminating unwanted moisture sources allowing the mold to grow. If there’s standing water, get it pumped out. If things are wet, dry the area with heat and fans. Your first task is to make sure mold stops growing while you’re cleaning up. Got some water damaged drywall or wood paneling? Tear it out. Have an old, musty carpet in your basement? Throw it away.

In the future, make sure your house is properly ventilated and leak-free. Do whatever is necessary to keep moisture levels too low for mold to grow. Then spray all areas of existing mold on non-removable surfaces with a non-toxic fungicide, or call in a mold removal specialist.

Steve Maxwell
Steve Maxwell is an award-winning content creator who has published more than 5,000 articles, shot countless photos and produced video since 1988. Using his experience as a carpenter, builder, stone mason and cabinetmaker, he has created content for Mother Earth News, Reader's Digest, Family Handyman, Cottage Life, Canadian Contractor, Canadian Home Workshop, and many more. Steve lives on Manitoulin Island, Canada with his wife and children in a stone house he built himself. His website gets 180,000+ views each month, his YouTube channel has 58,000+ subscribers and his weekly newsletter is received by 31,000 subscribers each Saturday morning.