Mold is a fungus that thrives both inside and outside your home.
Black mold -- the words alone are enough to make you cringe. It's the last thing you need in your home. Any mold can cause problems for people who are allergic, of course, but those molds referred to as "black" or "toxic" are particularly dangerous. Chances are, if the conditions inside your home are hospitable to mold, you're going to have it. If you suspect the mold is "black" or toxic, however, consider hiring a professional to remove it for you.
Black and Toxic Molds
The term "black" mold is misleading at best. First, while the terms "toxic" and "black" mold are commonly used interchangeably, only one is recognized as black mold by most professionals: Stachybotrys chartarum, sometimes called Stachybotrys atra. Other common indoor toxic molds include -- but are not limited to -- Cladosporium, Penicillium, Aspergillus, and Alternaria. Furthermore, Stachybotrys isn't actually black, but a greenish-black color instead. Finally, with more than 100,000 known types of mold, many of them are black. Unless they are Stachybotrys, however, they aren't "black" mold and may not even be toxic.
Another misleading term is "toxic." As the Centers for Disease Control explains, the mold itself isn't actually poisonous. Some molds are, instead, "toxigenic, meaning they can produce toxins (specifically mycotoxins)." These chemical compounds sometimes attach to mold spores -- reproductive seeds -- and drift away in search of a new home. When they are inhaled, they may cause serious health issues. Fortunately, mold generally only releases spores when it is disturbed, such as by the breeze of a closing door or the vibration of a pounding hammer. In addition, the mold doesn't release mycotoxins constantly, so even if spores are released, toxins may not. However, any mold is never healthy in a home -- much less Stachybotrys -- especially for individuals with lung problems, compromised immune systems or simply allergies to mold.
Signs of Black Mold
To tell if black mold may be growing in your home, just follow your nose. A musty, earthy smell, like dirt and rotting leaves, is a telltale sign of mold's presence. Stachybotrys smells especially strong. All molds need food, water and a dark, stagnant environment with temperatures that neither freeze nor boil to grow. Stachybotrys likes it a little wetter than some, feeding on water-saturated cellulose-based material such as cotton, wicker, drywall, lumber, cardboard and even dust or lint. If your home has flooded or you notice excessive moisture on or around building materials, possibly even dark rings on drywall indicating moisture damage, the conditions are ripe for black mold. The smell almost guarantees mold. But even if you see mold, that's no guarantee that it's black mold.
To Test or Not To Test
Stachybotrys is usually greenish-black and somewhat slimy or wet, but may also appear grayish with a sooty, powdery texture. Additionally, other molds may look similar. That's why it is impossible to tell if any given mold is black mold by looks, smell or even location. The only way to determine a mold species is examination under a microscope. Testing is costly, advises the CDC, and isn't really necessary. Any mold can cause health problems, as they point out. Therefore, you should arrange to have any mold in your home removed, no matter what type it is.