EPA Mold Resources
Federal recommendations about testing for mold.
Minnesota Department of Health
Reasons why not to test
Should I have my home tested?
One of the most common questions homeowners have is "How do I test for mold?" Most experts will discourage you from testing for mold because it is usually not necessary to indentify the specific mold, and test can be quite costly. Testing to determine the kinds and amounts of mold present is rarely helpful. No single test for mold can detect all types of mold, and the results can only estimate the amount of mold present, and only for the time the sample was taken.
Problems can also occur in the interpretation of the results, and findings may produce false negative results. Additionally, test results are not predictive of health risks. To date neither the Environmental Protection Agency (EPA) nor any other federal agency have set limits for mold or mold spores there is no way to determine a "safe" level of mold in the home since molds can be found everywhere indoors and out.
What is sometimes done is to compare the indoor level of one type of mold species against the same species outdoors. That may be in an indicator of higher mold growth in the home.
If you decide to pay for environmental sampling of molds, before the work starts, ask those doing the work to establish the criteria for interpreting the test results. They should tell you in advance what they will do or what recommendations they will make based on the sampling results. The results of samples taken in your unique situation can't be interpreted without physical inspection of the contaminated area, or without considering the building's characteristics and the factor that led to the present condition.
Detecting Mold in the Home
The best way to detect mold in the home is by seeing or smelling it. Look for areas where mold may be visible. Mold may be any color: black, white, red, orange, yellow, blue or violet. Also look for discoloration of building materials where previous water damage may have occurred, such as drywall or plywood.
Another way to identify the presence of mold is through the odor associated with it. A musty or earthy smell often indicates the presence of molds. If you have ever walked into a closed up home or entered an old building, you may have smelled mold. Sometimes your nose tightens up, or you might even get a headache. Located where the odor is the most intense to see if you can see mold growing. Since the sense of smell decreases rapidly, it is best to smell for mold after being away for awhile.