Interpretation: Is Mold Testing a Pass or Fail Test?
Mold testing is not a pass or fail test. The EPA has very specific guidelines on other environmental concerns like Radon gas for example and the EPA has clearly stated radon testing and mitigation protocols. Unfortunately no Federal guidance currently exists for Mold which is why mold testing results almost always need some sort of interpretation and Mold testing is best done with a home inspection. The home inspector will interpret the results based on the observations made during the inspection and will also use their experience analyzing other results as a reference to help inform the buyer.
Spore Samples results taken from the home are always considered in relation to the outdoor control sample. If higher than typical spore counts were observed outside than higher than typical counts will be expected the home because people, pets and objects are always being brought into the house from the outside. This is one reason why the test result is always relative.
What can effect a Mold Test?
Spore counts in the home can vary depending the Season, Weather, pets/occupants and their living habits, and many other factors. Sometimes a wet piece of clothing brought from the outside can significantly effect a test result. Dehumidification can reduce moisture and the number of spores in the home (which is good) however sometimes dehumidifiers can be placed to intentionally hide moisture issues-- unfortunately this is always a limitation.