Common Sampling Techniques Used in Mold Testing

Mold infestation is often a hidden hazard, potentially causing a variety of health problems which can be notoriously hard to diagnose. An important step in addressing this issue is mold testing, with accuracy paramount to ensure effective remediation. Here is a review of the common sampling techniques employed in mold testing to help you understand them and achieve a healthier and safer living environment.

Air Sampling

Air sampling is a mold analysis approach typically used in closed spaces. Both viable and non-viable methods exist for taking air samples. For a sample to be considered "viable," the spores must still be alive and able to reproduce at the time of analysis. Instead, non-viable sampling catches both living and non-living spores for further study.

Sampling air for the appropriate amount of time is essential for avoiding data loss due to overflowing cassettes. Indoor environments with moderate activity levels are measured less frequently than those with moderate activity outside.

Culture plates, spore traps, and routine air tests are all viable options for collecting air samples. While spore traps can detect mold types to the genus level, they might mark some spores as "unidentified" due to their limited specificity. To conduct a standard air test, a certain amount of air is drawn from a room using a portable air pump with a low airflow which is then compared to air drawn from elsewhere.

Bulk Sampling

Bulk sampling is typically utilized when taking a sample from a moist surface. The goal of a bulk sample is to determine what kinds of molds are prevalent in a specific location. To accomplish this, the lab collects fragments of flooring and drywall that are manageable for transport and handling. After that, you may either grow the sample in a lab to identify the species or examine it under a microscope directly to determine the genus.

Bulk sampling can accurately represent the variety of molds in a structure. This is because, especially in cases of widespread mold contamination, one sample might not be representative of the various varieties of mold present.

Tape Lift Sampling

Tape lift sampling is a reliable and non-destructive technique used in mold testing to determine the species of mold present in a given location. For this technique, a clear sticky tape or slide is utilized to gather a sample of the stain, as well as any settled dust or spores. After the sample and adhesive tape are combined, the bag is sent off to the lab for additional examination.

The primary goal of tape lift sampling is to identify the kinds of molds that have colonized a certain area. This is done by inspecting the sample under a microscope after gathering it on the transparent adhesive tape or slide. For sampling obvious mold growth, this is the method of choice since it permits a thorough analysis of the mold without damaging it in the process.

Swab Sampling

Surface swab sampling involves taking a sample from a place where mold growth is considered present using a clean swab. This can be regions where mold is growing or places where there are no signs of mold in sight but where contamination is still a problem. After collecting the sample, it is submitted to a lab for testing.

Surface swab sampling permits the determination of the genus and species of molds in the sample. This can be useful for gauging the extent of the mold outbreak and devising a strategy to fix it.

Areas without apparent mold growth benefit greatly from surface swab sampling. This may include exploring less obvious locations, such as under rugs or behind furniture. Taking samples from these spots will help find mold growth early on before it spreads. It is also helpful in estimating how widespread mold development is in an area.

Contact us at Household Environmental for mold remediation services should you find or suspect the presence of mold in your home.