Air Sampling
Air sampling collects airborne mold spores using a pump and cassette over a set time period. The sample is analyzed at a laboratory and compared to an outdoor control sample. Elevated indoor spore counts relative to outdoor levels indicate a mold source inside the home. Air sampling is the most common method for post-remediation clearance testing.
Surface Sampling (Swab and Tape Lift)
Surface swabs and tape lifts collect spores from a specific surface for species identification. Useful for confirming that a visible growth is mold and identifying the species, including whether it is Stachybotrys (black mold). Surface sampling does not measure the overall air quality of the home.
Bulk Sampling
Bulk sampling removes a physical piece of suspect material — drywall, ceiling tile, carpet — for laboratory analysis. Used when there is visible discoloration that may or may not be mold. Provides definitive identification of mold species within a material. Requires cutting out and replacing the sampled material.
ERMI Testing (Environmental Relative Moldiness Index)
ERMI is a dust-based DNA analysis that tests settled dust for 36 mold species associated with water-damaged buildings. It provides a single index score. ERMI is useful for identifying whether a home has a history of water damage-related mold even if no visible mold is present. It is not recommended as a standalone clearance test after remediation.
Home Test Kits vs. Professional Testing
Consumer mold test kits from hardware stores have significant limitations — they can detect whether mold is present but cannot accurately quantify airborne spore levels or confirm a successful remediation. Professional sampling by a certified industrial hygienist provides defensible results that can be used for insurance claims, real estate transactions, and remediation verification.
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