Mold Testing

There are several different types of mold testing that we can do based on what you need to get out of it.

Surface Testing

Surface testing is either using a “sterile swab” or a “tape lift” to determine what type of visible mold is on your surface(s). This type of testing is often used to prove or disprove the presence of mold or to determine the type(s) of mold that may be in your home.

Air Testing

An air test is taking a measured amount of air for a measured amount of time across a cassette (spore trap) which has a sticky microscope slide attached inside of it. This sticky slide captures spores that are currently airborne (what you are breathing) when the test is being taken. There are many factors that come into play when doing an air test so having a knowledgeable professional that knows where to take the test and under which conditions to take the test is key. These tests can provide a false positive as well as a false negative based on conditions, locations, and the current environment in which the test is taken.

In addition an air test needs at least one control sample sometimes two to be accurate. What we do is take the inside test(s) and then compare the outside test(s). As an example let’s say we have a spore count of 1,000 Cladosporium outside and we have a 2,000 count of Cladosporium inside then we have what would be considered elevated levels. The photo to the lower right is the Master Indoor Environmental Specialist preforming an air test before remediation.

An example of a false positive would be someone just walked through the yard to get to the house and has significant outside mold spores on their shoes and pants. The individual then takes the test or is even present during testing. The spores from the yard can provide a false positive.

A good example of a false negative is taking an air test in a basement but the Stachybotrys mold is behind the finished wall in the basement and although it is there it is not currently producing airborne spores for the air test to pick up. This means there could be mold in the basement but not currently active giving us a false negative. There can be visible mold during an air test but there are conditions where the mold is dormant at the time of the test, again giving us a false negative.

In addition outside air testing should be done while spores are active. In the beautiful state of Wisconsin there are months where there are no airborne spores due to snow covering the ground and other greens does not give us a good comparison of inside to outside. Although those of us that have been providing air tests for years should still be able to look at the report and be able to tell if there is an issue inside the house. It doesn’t mean we can’t do the test it just becomes more challenging.

Air testing results can typically be obtained within 24-48 business hours of sampling.

Clearance testing or PRV (Post Remediation Verification). PRV testing, often called clearance testing, is done after a professional clean up or Remediation of an affected area. This is also an air test and it is best that the clearance testing be done within 24 hours of the completed remediation so that any rouge spores do not give a false failure of the test. Again care should be taken not to “bring in spores” to a contained area during a PRV test. Many people try to do their own clean up and then request a PRV test. Unless containment was used (picture of typical containment to the right) the PRV can show a false positive from another area. Some people have been able to clean up their mold issues and pass a test. I need to tell you that most do not and we end up doing several tests wasting money that could have been put toward professional remediation. We always do a visual investigation of the affected area before we even do a test as many times there is still visual mold giving indication the remediation efforts were not done properly.

ERMI Testing. Environmental Relative Mold Index (ERMI) was developed by scientists at the EPA (Environmental Protection Agency). An ERMI test is a standardized objective test used to quantify the indoor mold burden in a building. The ERMI test looks for the DNA of mold in a dust sample. Molds that cause health problems are listed in group 1 (26 kinds). Molds that don’t typically cause health problems are listed in group 2 (10 kinds) in the ERMI report.

The ERMI test is representative of mold levels over time rather than a “snap shot” of the current state of mold spores in the home (like air testing). It has many uses, including helping to determine if a home has suffered water damage in the past that had resulted in mold. This is because the initial study included homes that had suffered water damage resulting in mold so the DNA being tested specifically includes molds that are commonly found when there has been water damage in a home.

The hope is that further research will enable the ERMI to assess health risks for susceptible individuals and provide a method for screening homes for mold.

According to the EPA, “The ERMI should be used only for research. The ERMI has not been validated for routine pubic use in homes, schools, or other buildings.”

The EPA website contains the following disclaimer:  “The EPA has not endorsed or validated any tools or methods to determine mold burden in homes including MSQPCR and ERMI. The EPA licensed this test to laboratories including EMLab P&K. However, the transfer of this technology under the Federal Technology Transfer Act cannot be used to make any claims suggesting that the ERMI is an EPA-approved or validated test."

False positives from dust testing can come from a variety of places. One would be, based on how old the dust is that a positive result can show up from a water event many years ago that was cleaned up but the dust remains. In other words we cannot always tell if it is current mold in the home or office. Elevated conditions can also occur when too many places are sampled with one test; basically counting the amount of mold spores multiple times.

False negatives can show up if the area tested has just recently been cleaned. Since the EPA has not endorsed ERMI testing Milwaukee Mold Inspector rarely performs this type of testing.

ERMI testing results

take about 10 business days.  

HERTSMIA-2

This test is similar to the ERMI test. It is a dust test that many labs offer but because there is no quantification there is no way to know how much mold is in the building. Typically you are instructed to take several samples with a dust cloth and then send them in to the lab for analysis. What is lacking in this test is to be able to count the mold levels. In other words if you take a dust sample from on top of the door in the living room and another sample on top of the door in the kitchen and yet another sample from the duct work…Are you testing the same mold over and over which gives you high concentrations?  Basically this test may show you what types of mold you have had in the house. But there is no way to determine if you are counting multiple times. In addition a dust test often gives you a history from an event that happened years ago but was now cleaned up.

Mycotoxin Testing

There are two tests available for Mycotoxin testing. Both are dust tests and are diagnosed by testing for mold DNA in the dust. Many Doctors are often looking for Mycotoxin testing so they can compare the results to blood tests. The first test is a mycotoxin panel which gives us 16 mycotoxins. The second test is called EMMA (Environmental Mold & Mycotoxin Assessment) which will provide the 16 mycotoxins and checking for 10 of the most toxigenic molds. These reports can be a bit confusing and often require a professional to figure out where the real issues are. Just as in ERMI testing there can be both false negatives and positives since we are relying on gathering dust.

Many people have done their own dust test and then requested we help them understand their results. Unfortunately, most of the time, the testing was improper and results are false or skewed.

Mycotoxin testing results take about 10 business days

Allergen Testing (ELISA) Enzyme-Linked Immunosorbent Assay

Indoor allergens from dust, dust mites, cockroaches, rodents, and pets (including cats, dogs, and birds) are known to cause allergic reactions and respiratory disease in sensitive people at residential and occupational settings.

Allergen sampling is taking a dust sample (or several) from the carpet, couch, chair, mattress, etc. and sending it to an accredited laboratory for analysis. Typically we are looking for excess dust and dust mites, cat, dog, avian, and cockroach allergens. We often use this test after mold testing comes up as no elevated levels yet we have some occupants of the home with allergy like symptoms that were thought to be from mold.

This type of testing can provide false negatives if the testing area has recently been cleaned, such as carpet, couch, etc.

Other Testing

In addition to mold testing we can provide VOC (Volatile Organic Compound) testing which looks to see if there are any chemical(s) in your home or office that is making you sick. We also can do Bacteria testing. For the bacteria testing we are typically doing a surface test but looking for bacteria instead of mold. This type of test can be utilized in restaurants, kitchens, and after a sewer back-up.

Formaldehyde testing is also available.

If you have made it this far down the page you may be asking yourself which test is best and which one will give me the results I need. After doing this for many years we have discovered that there is no “silver bullet” that may give you exactly what you need. However we can certainly come into the area of your concern and discuss your options. You may be surprised that testing may not be needed after all. Give us a call and let us help.