Why Air Quality Testing Matters
Something in your home doesn't feel right — a smell that won't go away, health symptoms that clear up when you leave, or a water event you're not sure was fully resolved. Before you can fix it, you need to know what you're actually dealing with. That's exactly what this testing is for.
Visible mold is only part of the story. Airborne spore concentrations can be significantly elevated in spaces where visible growth is limited or entirely hidden — inside wall cavities, within HVAC systems, or behind finished surfaces. Conversely, dramatic-looking surface mold may not be producing the elevated spore counts that create health risk if it has dried out and become non-sporulating. Without sampling, you're working from incomplete information.
Indoor air quality testing provides objective, documented data about what is actually present in the air and on surfaces. That data serves multiple purposes: it quantifies whether a problem exists and at what severity, it guides the scope of remediation by identifying affected zones, and it provides defensible documentation for real estate transactions, insurance claims, and in some cases medical and legal proceedings. At Sick Building Group, all testing is designed to produce actionable results — not just data for its own sake.
Types of Sampling We Perform
- Spore trap air sampling — The most common method for indoor air quality assessment. A calibrated air pump draws a measured volume of air through a cassette containing an adhesive-coated slide. The slide is analyzed under microscopy by a certified laboratory to identify and quantify fungal spore types by concentration (spores per cubic meter of air). Outdoor control samples are always collected for comparison
- Tape lift surface sampling — A clear adhesive tape is pressed to a suspect surface and submitted for laboratory analysis. Identifies the specific mold genera present on a surface and whether growth is active. Useful for characterizing visible or suspect growth before remediation and for targeted investigation of specific materials
- Bulk sampling — A physical sample of material (insulation, drywall, wood) is collected and submitted to the laboratory. Provides definitive identification of organisms within a material rather than on its surface. Used when tape lift is insufficient or when the interior condition of a material is in question
- ERMI (Environmental Relative Moldiness Index) — A dust sample collected from settled dust in the home is analyzed using MSQPCR (mold-specific quantitative polymerase chain reaction) to identify and quantify the DNA of 36 specific mold species. Particularly useful for characterizing overall building history of mold exposure and for documenting past water damage events
- Particulate air monitoring — Our real-time instruments count airborne particles by size to identify rooms or zones with elevated concentrations during inspection. (Biological species identification: coming soon)
What Laboratory Analysis Reveals
Certified laboratory analysis of air and surface samples identifies mold at the genus level (and in some cases species level) and quantifies concentration. The laboratory report provides raw counts and calculated concentrations, and our written interpretation report explains what those numbers mean in the context of your specific building and situation.
Key data points from laboratory analysis include total spore concentration compared to outdoor baseline, the ratio of indoor to outdoor spore counts, the presence of indicator species associated with water damage (Stachybotrys, Chaetomium, Aspergillus/Penicillium), and the diversity of genera — unusually low diversity with high concentration of a single genus is a common signature of active amplification within the building.
Real-Time vs. Laboratory Analysis
Particulate counters provide immediate on-site data during the inspection — useful for mapping where concentrations are elevated within the building, identifying the rooms or zones most affected, and guiding where to collect laboratory samples. Real-time instruments count particles by size and optical characteristics; they do not identify species.
Laboratory analysis of collected samples provides species identification and precise quantification, but requires a multi-day turnaround. The combination of real-time monitoring during inspection and laboratory analysis of collected samples gives the most complete picture: immediate directional data on the day of inspection, confirmed by certified laboratory results within the week.
Interpreting Results
Raw laboratory data without interpretation is often confusing and occasionally misleading. Spore counts that appear alarming in isolation may be entirely normal for outdoor conditions on a given day; counts that appear low may still represent a problem if the wrong genera are present. Our written interpretation report contextualizes all results against outdoor controls, compares room-to-room variation, identifies the significance of detected species, and provides clear conclusions about whether the tested environment reflects normal fungal ecology or elevated microbial contamination.
When Testing Is Appropriate — and When It Isn't
Testing is appropriate when: visible mold is present and the extent or type needs characterization; symptoms suggest air quality problems but no visible source has been identified; post-remediation clearance verification is required; real estate transactions require documented air quality data; or insurance or legal proceedings require objective third-party documentation.
Testing is not always the right starting point. If visible mold growth is extensive and the moisture source is evident, beginning with remediation rather than testing is often more efficient. Testing a wet or actively water-damaged building before the moisture is controlled can also produce misleadingly variable results. We'll give you an honest recommendation about whether testing or inspection is the right first step for your situation.
Post-Remediation Clearance Testing
Clearance testing after mold remediation is the final quality verification step — conducted by a party independent of the remediation contractor. We perform post-remediation clearance testing for jobs we complete as well as work done by other contractors. Clearance samples are collected after containment teardown with air scrubbers no longer running, compared against outdoor controls and pre-remediation baselines, and evaluated against IICRC S520 Condition 1 criteria. A written clearance report is provided that documents pass or fail status for each tested area.
Frequently Asked Questions
What are normal mold levels indoors?
There is no regulatory standard that defines a universally "safe" or "unsafe" indoor spore count. The most useful reference point is the outdoor control sample collected at the same time. Indoor spore concentrations should generally be equal to or lower than outdoor concentrations. Elevated indoor counts — particularly of water damage indicator species like Stachybotrys or Chaetomium — at any concentration are significant regardless of absolute numbers. We interpret results in full context rather than applying a single threshold number that lacks scientific basis.
How long does it take to get laboratory results?
Standard laboratory turnaround for spore trap and surface samples is 3–5 business days. Rush processing (24–48 hours) is available from our laboratory partners when needed for time-sensitive transactions or urgent situations. ERMI analysis typically takes 5–7 business days. Our written interpretation report is delivered promptly after we receive laboratory results.
Can I test my own air quality with a home kit?
Consumer home mold test kits — the kind sold in hardware stores — are unreliable for meaningful air quality assessment. Passive petri dish collection methods are uncontrolled, unquantified, and not analyzed to professional standards. They produce results that cannot be meaningfully compared to any reference and are not accepted for real estate, insurance, or legal purposes. Professional sampling with calibrated equipment, outdoor controls, and certified laboratory analysis is the only method that produces actionable, defensible data.
What does a clearance test involve?
A post-remediation clearance test involves air sampling in and around the remediated area after all work is complete, containment is removed, and air scrubbers have been off long enough for settled conditions to re-establish. We collect samples using the same spore trap methodology as pre-remediation sampling, along with a fresh outdoor control. Laboratory results are compared against the pre-remediation baseline and evaluated against IICRC S520 clearance criteria. A written report documents the results and whether clearance was achieved in each tested area.
Do you provide reports suitable for real estate transactions?
Yes. Our written inspection and testing reports are formatted for use in real estate due diligence, insurance claims, and legal proceedings. Reports include chain of custody documentation for laboratory samples, certified laboratory analysis, photographic documentation, and written findings and conclusions. We can accommodate compressed timelines for inspection contingency windows — contact us to confirm current scheduling availability.