What is Black Mold? Is it Toxic?

When most people think of mold, they think of the black growths on their bathroom walls, the stains under their sink, or the speckles on their wall.

When people are asked to describe toxic mold, most respond by saying its black in color.

Let’s debunk some myths by stating these facts:

  • Not all mold is toxic.
  • Not all black colored mold is toxic.
  • Toxic mold types can be other colors than black – white, gray, orange, etc.
  • Toxic types of mold are not toxic by themselves. It’s the byproduct they release during growth called mycotoxins that is toxic to humans and animals.
  • Non-toxic mold can be dangerous, as well, to certain types of individuals or under certain conditions.

The reason behind the mindset of so many that black mold is toxic is due to one particular kind of mold that is often found in properties contaminated with mold. It is toxic, it is black, and it can lead to some severe health conditions following exposure. It is called Stachybotrys chartarum.

Stachybotrys is the mold people often see in pictures of black mold and is the mold usually referred to when people refer to toxic mold indoors, black or otherwise.

If Stachybotrys is found inside of a property following a mold inspection, at any elevated level, it is recommended that remediation and decontamination of the property be pursued to ensure the safety of occupants.

Finding a Mold Company: If you have decided that you would like to seek out a mold company to provide you with information about inspections, testing or remediation, click here to find a certified company in your area.

Learn More About Mold: To learn more about mold, how it grows, and its impact on our indoor environment and human health, visit the What is Mold? page.


About author

This article was written by Dr. Phillip Blanchett, MD

Dr. Phillip Blanchett is a licensed physician who specializes in Pulmonology and Otolaryngology. Born in Brooklyn, New York, Dr. Blanchett graduated from Cornell University and attended Weill Cornell Medical College. His graduate and post-graduate studies were completed at University of California, Davis. He completed his residency at the St. Francis Memorial Hospital in San Francisco. Currently, he lives in the San Francisco where he researches respiratory and pulmonary illnesses at UCSF.


Comments (3)
  1. Ed says - Posted: November 24, 2012

    When the mold is the result of a temporary condition, such as a flood of salt water from the bay, is it likely to be Stachybotrys? How might this compare to the mold seen at the point of a water leak, be it from the supply lines in a house or from rain water?

    thanks ed

  2. Donna J. Tanaka says - Posted: December 17, 2012

    I’ve had a mold and mildew problem in my bathroom ceiling since at least 6/10/12 (when I sent my first video to my landlord)I continued to complain about this problem, spraying my ceiling with bleach as she advised. She said it was moisture from my shower and that I needed to leave my window open, which I did 24/7. In early October, I could hear continuous dripping, even as late as 6 hours after the tenant upstairs had bathed. She ignored this as well, when part of the bathroom ceiling was pouched and falling and I sent her the video of this, she finally sent a worker over to open up the ceiling in early October. I sent off a mold sample to one of those $40 mold testing places. The report I got from this test didn’t get her attention, and she was still ignoring me. On 10/20/12 I got an air purifier for my bedroom as I was experiencing hoarseness, sore throat, eye infections, etc. I tried to stay in my room, but, I knew that the 2 ft x 3 ft open hole in my ceiling was the cause. She couldn’t find someone to close the ceiling, that would do it for the amount of money she considered reasonable. In my frustration I contacted someone that I knew to look at problem. When he climbed the ladder and looked in the hole, he told me that there was a yellow carpet of mold inside my ceiling…..which I passed on to my landlady, again she discounted this new disclosure. The day after thanksgiving my son climbed a ladder and took a video. That was it for me, I immediately moved in with a friend, because I couldn’t stay there anymore. I then got an atty and had a mold test done
    By H.M.Pitt, inc. in San Diego. The living room sample showed 71 counts/m3 and a raw count of 1 for Stachybotrys. In the ceiling scraping the report showed high Cladosporium and moderate Stachybotrys, and the report suggested mold remediation specialist do the work.
    My question is, is 71 counts/m3 in my livingroom too much? I’m a 70 year old (healthy before this, female)
    Donna Tanaka

  3. David says - Posted: December 20, 2012

    More of a question. Is there any danger ( besides the normal precautions taken while cleaning )
    More so, can black mold become airborn due to cleaning with bleach/water

Reply Click here to cancel reply.

Your email address will not be published. Required fields are marked *

* Copy This Password *

* Type Or Paste Password Here *