Here's How to Tell If the Mold in Your House Is Dangerous

Published October 1st, 2019 by Devteam

Discovering mold in your home may be a cause for alarm, but it doesn't mean you're under the gun yet.

See, in these situations, the real question is, "What kind of mold is dangerous?" While some molds are a threat to human health, others are merely a hindrance. To proceed accordingly, you must know what you're dealing with.

Not sure how to identify dangerous mold? Here's a quick rundown.

Dangerous Mold Growth

Dangerous molds grow in the same areas as all other molds. Any dark place that accumulates moisture is a potential breeding ground. In the right conditions, mold can grow on any kind of organic surface.

As for moisture sources, they can be anything from a flood to high humidity. The most common sources are leaks that allow water from the outside to seep inside your home.

Though not all molds are toxic, there are five categories that can make life difficult for you. These are Stachybotrys, Cladosporium, Penicillium, Fusarium, and Aspergillus. Here's why they're bad for you and how you can identify them.


This extremely dangerous type of fungus is best known as "black mold." Species under this genus produce mycotoxins whenever they're disturbed. They often grow on wood, ceiling tiles, cardboard and other materials containing cellulose.

Stachybotrys can cause severe illness in infants, the elderly, and people with weaker immune systems. Common exposure symptoms include respiratory issues, sinus congestion, chronic fatigue, and so on.


This common genus comes in brown, grey, black, and green colors. It often develops on painted walls, carpets, wallpapers, and other damp surfaces. It's comprised of 40 species and may cause pulmonary edema and emphysema.


There are approximately 200 known species of Penicillium. They're all found in air or soil, and their colors range from yellow and blue to white and green. Their presence often indicates high moisture levels in the environment.

Though their main angle of attack is causing food to spoil, these molds can cause serious illnesses as well. Examples include asthma and nail fungus, as well as infections of the liver, lungs, and kidneys.


These mold spores usually grow on water-damaged fabrics and carpeting. Prolonged exposure to them can cause asthma, allergic reactions, and respiratory conditions. Fusarium is also linked to some gastrointestinal illnesses.


The least serious mold group on this list, Aspergillus consists of close to 200 species. Only 16 of those are harmful to humans, and none are fatal if treated. This type is yellow-green in color and is usually encountered indoors.

Neglecting the presence of this mold can lead to respiratory infections. In rare cases, Aspergillus can cause inflammation of the lungs. This condition goes by the name of hypersensitivity pneumonitis.

More on What Kind of Mold Is Dangerous

With thousands of mold species in the world, it's hard to avoid them completely. Of course, this doesn't mean that we have to invite them into our homes. That's why you should strive to keep your home moisture-free at all times.

Still not sure what kind of mold is dangerous? Need some help in removing toxic mold growing inside your home? Contact us here to get clear about what mold species you have, and the best way to remove it. 

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