Blue Mold - What It Is & How Dangerous or Toxic It Could Be

By: Licensed Mold Assessor Brad Fishbein

August 7, 2018

You eat mold...

No, for real I am being serious!

Think about it, did you know that mold is added to blue cheese? Yup, you read it right!

Blue mold can grow on many different foods.

Ironically, some of those foods can still be eaten after the mold is cut out!

While all this food talk may be getting you hungry (or making you sick), what you really need to be concerned with is blue mold growing on walls and other building materials in your home.

French painter names Raoul Dufy once said,

“Blue is the only color which maintains its own character in all its tones… it will always stay blue"

I am going to disprove that, so let's explore blue mold!

What Is Blue Mold?

Blue mold, caused by Penicillium expansum, is the most economically important postharvest disease of stored fruit and vegetables. It can also grow on household materials and furnishings damaged by water and plants with wounds. It causes circular lesions on plants and produces toxins, including patulin, that may make you sick if ingested. Discard contaminated food.


What Is Penicillium?

Just like all other colors of mold, there is no scientific name for mold that is blue in color.

Mold comes in many different shades and colors.

When you see blue mold it will usually be a species of mold called Penicillium.

Penicillium is very common both indoors and outdoors.

There are different strands of Penicillium and most of those strands will not cause health effects in humans unless you have an allergy to it.

There are a few strands that can make you sick.

Penicillium is actually where Penicillin was derived from. So think about, if modern medicine is used from Penicillium mold, it can't be bad for you, right?

Not necessarily...

Is Blue Mold Dangerous?

Even though blue mold can grow on food and it may still be able to be eaten, I wouldn't do it, would you?

And if we are talking about on building materials in the home...

Blue mold is usually a sign of water damage which means the blue mold is using whatever it's growing on as food. Because of this, it may produce airborne mold spores that you are breathing it.

So yes, blue mold can be dangerous.

Mold can start out as blue and if the area keeps getting wet, eventually Stachybotrys (the black toxic mold you hear about) can start to eat the blue mold and it will become black or green. That is why blue will not always stay blue!

How To Remove Blue Mold In The House

Removing blue mold will likely require mold remediation by a licensed professional because there won't usually be just one blue mold spot. It is generally a signal that there has been extensive water damage.

If you are going to attempt to remove blue mold by yourself, you should get proper PPE (personal protection equipment).

Building material should be removed under a containment barrier if over 10 square feet on blue mold is present. If you attempt to do mold removal by yourself without a proper containment, you run the risk of contaminating the entire home.

Air scrubbers should be brought into the home to remove the airborne mold spores that blue mold may produce.

Blue Mold In Food

As stated earlier, blue cheese is actually made from mold. That does not mean you should eat any food that has mold on it. Let me ask you, would you eat this:

Me neither!

Bottom line is:

If you have blue mold on any other type of food besides blue cheese, get rid of it!

Blue Mold Should Be Treated As If It Can Cause Harm

If you take proper pre-cautions, you can protect yourself from the health effects that MAY be caused by blue mold.

Meet the author: Brad Fishbein is an ACAC council-certified Microbial Investigator. In the fall of 2012, he became a Licensed Mold Assessor in the State of Florida through the Department of Business & Professional Regulation. Brad has helped homeowners with over 5,000 successfully completed Mold Inspections since 2009.

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