What is “Toxic” Black Mold

Angela Yost

By Angela Yost

“Toxic black mold” has been the villain in many horror stories in the news and on the Internet over the years. As professionals in the mold inspection and mold remediation industries, the most common questions we get asked are, “Do I have toxic black mold?” or “Is this black mold going to make me sick?” These questions are usually asked by frantic homeowners or distraught parents who have read these horror stories and automatically go to the worst-case scenario thanks to the pictures painted in these articles. They are quick to tell of these terrible scenarios, but they often forget to educate the common reader on what this “black mold” actually is.

Let’s take a step back in order to get better understanding of the mold that has been haunting homeowners and establish what black mold actually is, if it is in fact “toxic” and the effects of this mold.

What is Black Mold?

The infamous mold commonly referred to as “black mold” is Stachbotrys Chartarum, also known as Stachybotrys Atra. Stachbotrys has been nicknamed, “black mold” due to the greenish-black color that it colonizes in. As reported by the Center for Disease Control (CDC), black mold can grow on cellulose-based contents, such as fiberboard, gypsum board, paper, dust and lint and a constant moisture source, such as flooding, water infiltration, excessive humidity or condensation is needed for it to grow.

Although Stachbotrys has been dubbed, “black mold,” there are other allergenic molds that can colonize in black. The only way to know the genus or type of mold for sure is to perform mold testing.

Is Black Mold Toxic?

Contrary to popular belief, “toxic mold” is not an accurate term. According to the CDC, while certain molds, including black mold or Stachybotrys are toxigenic – meaning they can produce toxins – the molds themselves are not toxic or poisonous.

EMSL Analytical, Inc. has provided that Stachybotrys has the ability to produce the toxins Cyclosporins, Macrocyclic Trichothecenes, such as Roridin E; Satratoxin F, G & H; Sporidesmin G; Trichoverrol; Verrucarin J and Stachybotryolactone. Exposures to these toxins can occur through inhalation, ingestion or skin exposure.

Many of the reports of Stachbotrys Toxicosis are anecdotal and are still being researched. A few key points to remember is that the mold commonly referred to as “black mold” is Stachybotrys Chartarum and referring to it is “toxic mold” is a misnomer since the mold itself isn’t toxic, but rather has the ability to produce toxins. If you see black mold, it does not necessarily mean it is Stachybotrys. The only way to know the type of mold present is to test, so be sure to contact a professional if you have concerns of mold in your home.


Angela Yost is the director of sales and marketing for Mold Detection & Remediation Specialists, Inc., as well as a certified mold inspector and assessor. Angela graduated from Florida International University in 2009 with a degree in public relations. After working at a boutique marketing firm in Bridgewater, New Jersey, she joined the Mold Detection team in 2010. Angela is committed to staying up-to-date on industry news and techniques and sharing her knowledge with clients so they can properly address any mold issues. For more information, please visit RemoveTheMold.com.