Is it Necessary to Test for Mold Indoors?

Abita Springs, LA


This is a great question because the answer has been changing over the years, and that, I think, to the better!  Traditionally, the position has been taken that mold testing is unnecessary so that if you see mold you just clean it up, no questions asked.  That’s quick and simple but could be problematic for a variety of reasons.

Mold is ubiquitous: a very big word for just saying that mold is everywhere.  Its presence outdoors is not much of a problem because its diluted by the huge volume of air.  Indoors is another question because our environments are tightly sealed and much of the air is turned repeatedly with very little fresh air coming in from the outside to dilute it.  Mold spores settle on a surface, find a nutrient and a little moisture and voila, you could have a problem.  But can you tell if its mold without testing.  The answer is NO.  It might look like mold but could be insect remains, feces or just generic dirt.

The EPA has an interesting document that we show in our classes demonstrating the confusion and disconnect that has plagued our industry.  “If you see mold just clean it up” this document starts.  Then the very next sentence suggests “if litigation is likely, you might consider testing.”  In the very next paragraph, the document concludes by saying, “the only way to tell if it’s mold or dirt is to test it.”  So, might it be important to know whether you’re dealing with mold or dirt?  The answer is YES.

Knowing the difference between mold and dirt might help a doctor better diagnose symptoms someone having because of environmental sensitivity.  Some doctors prefer to know the specific genus of the mold, so they can treat the symptoms and that certainly can’t be determined by the naked eye.  A trained NORMI™ Certified Mold Assessor would want to know the genus to help determine where the water source might be.  Is this mold, that I’ve identified, getting its moisture source from behind the drywall, from an air infiltration issue or from the relative humidity?  The first place to start for the assessor is to know, for sure, that it IS mold.  A trained NORMI™ Certified Mold Remediator would want to sample the mold to make sure he’s created a baseline for his own files to which he can compare his PRV (Post Remediation Verification), confirming that he has substantially reduced the mold growth in the areas that were remediated or sanitized. 

The industry is changing.  NORMI™, the National Organization of Remediators and Mold Inspectors has led the way by writing the NORMI™ Professional Practices which requires all mold professionals to test what looks like mold.  There’s a fellow on YouTube who claims you can tell whether it’s mold or not by simply licking it.  Yes, licking it.  Though it makes me chuckle, it’s about as ridiculous as thinking you could tell by simply looking at it.  The trained mold professional takes both air and surface samples to determine the type of mold, the amount of mold, the source of the moisture that’s feeding and create a baseline for future testing.  Without testing, each one of those processes is simply a guess.  And probably not a very good one!

For more information on training and certification in the IAQ/Mold Industry, contact NORMI™ at or 877.251.2296