What is air sampling (mold testing)?

Air sampling for mold testing collects airborne spores using a pump-powered spore trap device that draws air across a sticky slide or collection media over a set time period, typically 5 to 10 minutes. The trap catches spore particles suspended in the air, which are then sent to a laboratory for analysis under a microscope. A technician counts the spore types and concentrations to determine what mold is present and at what level.

The key purpose of air sampling is comparison. A lab report shows both indoor and outdoor spore counts, allowing restoration professionals and property owners to establish whether inside air quality is elevated or normal. If indoor spore counts are significantly higher than outdoor baseline counts, it suggests active mold growth or contamination within the building. This method is especially useful after water damage events, where hidden mold may be releasing spores into occupied spaces before visible growth appears.

Air sampling differs from surface sampling because it captures what people are actually breathing rather than what sits on a single surface. Results help determine whether mold remediation work is needed, whether remediation was successful, and whether the building is safe to occupy. Outdoor samples are essential context for interpreting results, since baseline outdoor spore levels vary by season and location in the Charleston area.