Air Tests for Mold Inspections
by Timothy J. Rollins CEO Capstone Inspections, LLC
Aspergillus on Kitchen Cabinets
Utilizing Mold Test Kits Mold Inspection is important for many reasons. Mold spores are not visible to the naked eye. Typically they are between 1 and 30 microns in size. Now as a reminder for those of us that have been out of high school for a while a micron is a millionth of a meter. These types of mold can often be identified to the genus through laboratory analysis of the air test. Having Air tests analyzed by a certified laboratory can also help provide evidence of the scope and severity of a mold problem that was not able found during a visual inspection. This will also aid in assessing human exposure to mold spores. If visible mold is present then direct testing will be a more accurate method of identification. After any remediation, new air test should be taken to help ensure that the remediation was complete. Please see how to read How to read a Mold Report to better understand the results. The overall spore counts are not the only thing of relevance. A word of caution all the mold will never be removed unless you live in a positive pressured “Clean Room” in a hospital.
Air Quality Testing
Air testing and sampling can be used to gather data regarding what mold spores are present and in what quanties. This is when the questions arise about exposure, exposure levels, toxicity, and which are pathogenic. Please read Mold Exposure for a better understanding about mold exposure. These mold tests are taken by using a special air pump that forces air through a collection device at a specific rate and volume which allows mold spores stick to the media inside and can be viewed and identified by a laboratory to the Genus. If you can recall high school biology and the hierarchy of biological classifications which is how we classify all life forms. In order they are Life, Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. A lab visually can identify most molds to the Genus level. In order to identify the species they will have to use grow viable samples.
Air-Testing Devices
There are several types of devices used to collect air tests that can be analyzed for mold. Some common examples include:
- Impact Tests that use a calibrated air pump to impact spores onto a prepared microscope slide;
- Cassette Tests, which may be of the disposable or one-time-use type, and also employ forced air to impact spores onto a collection media; These are the most common option used by inspectors.
- Airborne-particle collectors that trap spores directly on a culture dish, sometimes call an Agar Plate. These may be utilized to identify the species of mold that has been found.
“To Sample or Not to Sample”, That is the Question
Air tests are generally taken if visual, non-invasive examination reveals not apparent mold growth, however conditions that could lead to growth, such as moisture intrusion, elevated humidity (above 60% RH) or water damage. Musty odors can also be a sign of mold growth. As a rule if you can smell it you have it! If no sign of mold or potential for mold is apparent, indoor air tests should be taken, 1 per floor or 1 per 1000 sq. of floor space. These tests should be taken in the most lived-in rooms of the house and near the HVAC System.
Outdoor mold air tests are also typically taken as a control for comparison to indoor air tests. One or two tests can be taken as a control. If more than one is taken outside then take one from the windward side and one from the leeward side of the building — will help provide a more complete picture of what is in the air that may be entering the house through windows and doors at times when they are open. It is best to take the outdoor air testing as close together in time as possible to the indoor test that they will be compared.
Certified Mold Inspectors should taking viable mold air tests for species identification if a person is under a physician’s care for mold exposure or if mold exposure treatment maybe soon. This may aid the physician in treatment for specific toxin or exposure.
Where to Sample and Ideal Conditions
Testing should start only after a though visual examination of the building. Tests should be taken any areas of a building suspected or confirmed to have mold growth, air tests can be taken to help verify and gather more information. Moisture intrusion, water damage, musty odors, apparent mold growth, or conditions conducive to mold growth are all common reasons to gather an mold air test. Air Tests should be taken near the center of the room, with the collection device positioned typically 2 to 4 feet off the ground.
The testing times can be reduced further if there is an active source of dust, such as from ongoing construction.
Testing should take place in livable spaces within the building under closed conditions in order to help stabilize the air and allow for the most accurate measurement. The building however cannot be vacant for a period of time as this will affect the overall spore counts. While the sample is being collected, windows and exterior doors should be kept shut other than for normal entry and exit from the home. It is best to have air exchangers (other than a furnace) or fans that exchange indoor-outdoor air switched off during sampling.
Weather conditions can be an important factor in gathering accurate data. Severe thunderstorms or high winds can affect the sampling and analysis results. High winds or rapid changes in barometric pressure increase the difference in air pressure between the interior and exterior, which can increase the variability of airborne mold-spore concentration. Large differences in air pressure between the interior and exterior can cause more airborne spores to be sucked inside, skewing the results of the sample.
Difficulties With Air Testing
It is helpful to think of air sampling as just one tool in the tool belt when inspecting a house for mold problems. An air test alone is not enough to confirm or refute the existence of a problem, and such testing needs to be accompanied by though visual inspection and other methods of data collection, such as a surface sample. Indoor airborne spore levels can vary according to several factors, and this can lead to skewed results if care is not taken to set up the sampling correctly. Also, since only spores are collected with an air sample and may actually be damaged during collection, identification of the mold type can be more difficult than with a sample collected with tape or a cultured sample.
Air tests are good for use as a background screen to ensure that there isn’t a large undiscovered mold source not yet found somewhere in a home. This is because they can detect long chains of spores that are still intact. These chains normally break apart quickly as they travel through the air, so a sample that reveals intact chains can indicate that there is mold nearby, possibly undiscovered during other tests and visual examination.
In summary, Air test are a valuable tool that an inspector can use to determine if a mold problem exists, however air testing alone is not sufficient to determine if a mold problem exists in the building. Air Testing along with a through visual inspection and using other tools when searching for mold are necessary to properly evaluate the building.
A though mold investigation using powerful tools such as Thermal Imaging, Moisture meters, and Air Testing by a certified Mold Inspector, Remediator and Thermogopher will provide you with the most comprehensive inspection and the peace of mind that your house is not a toxic environment. Call Capstone Inspections today (330) 806-2023. When integrity counts……Count on Capstone!