What Is Toxic Mold?

The term “toxic mold” is loosely used in the industry and has different meanings depending upon the user. It commonly refers to a group of molds capable of producing toxins and that have received a lot of attention in the media. The topic of mold and the toxins (more accurately called mycotoxins) they are capable of producing is very controversial. Fungi (a more accurate term than “mold”) produce hundreds of mycotoxins and some of these toxins are produced by some fungi commonly found growing indoors. However, you need to know some factors about the importance, or lack thereof, of fungal mycotoxins.

“Toxic Mold” – 7 Things You Need To Know

1. 1. Toxigenic means that the fungus is capable of producing toxins. It doesn’t mean that they always do, nor that the presence of a specific fungus can be taken to mean that the toxins are being produced. Even though a fungal species is known to have strains that produce mycotoxins, not all strains have this capability, and even those with the capability do not make the toxins under all conditions. Unfortunately, little data is available in these areas for fungi other than Stachybotrys, Aspergillus, and a few others.

 

Mold growth (Aspergillus) on wallpaper.
Source: EMLab P&K

 

1. 1. If you want to know whether or not toxins are present, you must sample for the toxin itself. There are an increasing number of toxin assays available. A caution about using these services: Be sure that any sample collection and mold analysis is hypothesis driven, and that your mold inspector knows how he/she is going to interpret the data.

 

1. 1. Mycotoxins are not volatile, and inhalation exposure is probably primarily related to airborne spores.

 

1. 1. Health effects for most of the “toxic molds” are known only from either agricultural environments or from laboratory experiments, and virtually all of the data involves ingestion, not inhalation, of the mycotoxins.

 

1. 1. In normal homes and offices, it’s unlikely and probably very rare to inhale enough so-called “toxic molds” (even the most toxic strains) to reach a dose that affects your health. This conclusion is based on the amount of toxin necessary to cause health effects by ingestion and the fact that the toxin content of individual mold spores is quite low.

 

1. 1. Concentrating on the so-called “toxic mold” in indoor environmental investigations is only appropriate if you are only concerned about specific symptoms that you are convinced could only be due to the mycotoxins. (Note: We don’t know what those symptoms would be.) If you ignore the other fungi and focus only on those known to cause toxins, you ignore potentially hazardous conditions that could lead to serious respiratory diseases.

 

1. Unless a qualified medical doctor is involved, mold investigations should usually be primarily focused on finding and eliminating unwanted sources of moisture and on properly removing mold.

While news media hypes up “toxic molds” and drives fear in the general public, it’s actually unlikely and probably very rare to inhale enough so-called “toxic molds” to affect your health in normal homes and office buildings.