Cashins & Associates Blog

Indoor Air Quality: Top 10 Things You Might Not Know About Mold

Posted by Zachary Keefe on Tue, Sep, 22, 2015 @ 10:09 AM

Mold_GrowthOver the past decade or so, mold has received a lot of coverage in the media. It seems that you couldn't go a week without hearing of another "toxic black mold" case, or someone's home being demolished because of a fungal infestation. Unfortunately, more information does not always lead to better understanding. Below are ten facts about mold that you might not be aware of:

1. Color does not indicate toxicity

We are frequently asked questions such as "Is this mold toxic, or just common mold?" 

Or, we get calls from worried building owners or occupants saying that they have discovered "toxic black mold." 

For the record, this notion of "toxic black mold" is, to a large degree, the result of misunderstanding fostered by ill-informed reporters and media outlets. Many types of common indoor molds are black in appearance. Whether they are "toxic" or not has more to do with whether or not you as an individual are allergic to that type of mold. Only in very extreme situations can toxins given off by mold have any kind of affect on a normal healthy person - and in these cases the color of the mold has nothing to do with it.

2. Mold does not require darkness to grow

I oftentimes hear people say that mold likes to grow in warm, damp, dark places, like the basement or an attic. Whereas it is true that many molds thrive in warm environments, and that mold requires water to grow, darkness is not required for mold to flourish. It may seem this way, since we often will find it growing in dark places. This, however, is coincidental - mold is much more likely to colonize and grow when there is no air movement to disturb it. Many locations that have excess water and little air movement will also be underlit. It has more to do with how often the spores are disrupted by human activity than it has to do with light. 

3. Mold does not need to be warm to grow

The common conception is that mold requires warm, moist environments to thrive. But, have you ever taken a sandwich out of the back of the refrigerator that has been there for a few months? I would hazard to guess that there was a good amount of mold on it, even though it was in a chilly location. The truth is, many molds thrive in temperatures between 60 - 80 degrees Fahrenheit, but not all. Some molds do quite well at temperatures well below this range, as moldy sandwiches will repeatedly remind us.

4. Why does mold smell?

I would hazard to guess that most people don't really know why mold has that distinct musty odor. In fact, this odor is only present while the mold is in the process of eating and growing. The odor is caused by gases resulting from the mold's metabolic processes. In other words, it is the result of "mold farts". Dried mold that is in a dormant state will not give off much of a strong odor. So, if you smell that distinct moldy odor, you can be sure that mold is present and growing.

5. Mold spores in "fresh" air

Some people claim that when they are inside a particular building or room they experience health effects related to mold, but when they go outdoors the symptoms disappear. This claim begins to appear curious after taking air samples inside and outside of buildings. Air samples can be useful in that they are able to show if certain types of molds are more prevalent indoors than out. In cases such as these, it may be the case that some mold growth is occurring indoors. Most of the time, however, even if there is a mold problem inside a building, the overall concentrations of spores in the outdoor air will dwarf the concentration of spores inside. We breathe spores in the outdoor air all the time, and with every breath. Healthy people don't really even have to think about this - the human body is surprisingly efficient at eliminating these spores before they can do any harm.

6. Mold/mildew

How often have you heard the claim that a product is effective against both mold AND mildew? Have you ever wondered what the difference is? The answer is - mildew is just a type of mold. It is whitish in color and grows mostly on plants. It can also show up in other locations, such as the shower or other similar damp places. Many times mildew doesn't require a full-scale remediation effort - just a wipe with a sponge and some mild detergent.

7. "Dead" mold spores

Many people assume that if the mold is simply killed - perhaps using a bleach solution or similar biocide - that there is nothing further to worry about. In fact, even dead on "non-viable" spores can cause negative health effects in certain individuals. Dead spores will impact indoor air quality in a similar fashion as live spores. This is why controlled removal of the mold contaminated material is more effective than simply applying something that kills it. 

8. There are no regulatory limits

There are currently no State or Federal regulations that require a specific protocol for bioaerosol air monitoring and inspection. Nor are there any workplace exposure regulations, such as Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PELs). The development of such limits is inherently fraught with problems, since mold levels are constantly changing, and due to the fact that each individual person will respond differently to the same types and concentrations of spores. For now, the industry standard understanding is that the concentrations of mold spores should be higher outside than inside, and that the types of molds found indoors should also be found outdoors.

9. Mold and bleach

Again, killing the mold is not the aim - the goal should be removal of the growth from the interior of the building. As was mentioned earlier, even non-viable spores can cause negative health effects in certain individuals. This is why the EPA, among other groups, does not recommend the use of bleach when removing mold growth. Bleach is a hazardous substance that can create safety issues for the end user. Extreme care must be taken when handling bleach; further bleach loses its efficacy quickly in the presence of organic material. Bleach is most effective when applying to "clean" surfaces. The EPA recommendation is to use water along with a mild detergent. Of course, if the material is porous or soft, and thus cannot be cleaned in such a fashion, it should be removed and disposed of.

10. Use of dust masks when working around mold

A standard home-improvement warehouse dust mask will not offer sufficient protection from airborne mold spores. In order to protect one's self during activities in which excessive concentrations of airborne mold spores are present is to use a half-face respirator equipped with P100 cartridges. However, it should be kept in mind that certain individuals may have difficulty breathing when working with such a respirator. Because of this, it is necessary to be evaluated by a physician prior to donning such a device. Extensive mold contamination should only be remediated by professional contractors.

If you have any questions regarding mold, please let us know in the comments below. We will do our best to answer them as quickly as possible.

If you are a commercial business, school, or hospital and are dealing with a mold issue we would be happy to assist. Please click the button below and an Industrial Hygienist will respond.

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