Air testing isn’t always necessary, and it can be very useful when it is. Short answer: mold air testing collects airborne spores, sends them to a laboratory, and compares indoor results with an outdoor sample taken the same day. The EPA says sampling is usually unnecessary when mold is visible. It helps most when mold is suspected but hidden. Here are 7 things to know.
1. What Air Testing Is
A technician draws a measured amount of air through a sampling cassette, often called a spore trap, that captures airborne particles.
Cassette goes to a laboratory
Examined under a microscope
Outdoor sample taken at the same time
Outdoor air naturally contains spores, so the outdoor sample is your baseline.
2. What the Lab Report Shows
A typical report lists:
Types of mold found
Spore count per sample
Indoor vs. outdoor comparison
3. How to Read the Results
There are no federal limits for mold spores and no health-based standard for an acceptable level, so results are read by comparison.
Indoor types similar to outdoor is typical
Types found indoors but not outdoors may signal a moisture problem
Levels well above outdoor deserve a closer look
A professional should interpret results alongside the inspection.
4. When Testing Is Worth It
Air testing helps when:
Musty smell with no visible source
After a leak or water event
Buying or selling a home
After remediation to confirm results
Ongoing symptoms and unclear cause
This is when mold testing in Spokane or CDA earns its cost.
Questions about your home? Call Us Now: 509.936.3567
5. When You Can Skip It
If you can already see mold, the EPA says sampling is usually unnecessary.
Remove the mold
Fix the water source
A test won’t change those steps.
6. What Testing Can’t Do
Be honest about the limits.
It’s a snapshot in time
Weather and humidity change results
A clean result isn’t a guarantee
Needs a clear purpose
That’s why we pair testing with an inspection.
7. What Happens Next
If testing and inspection point to moisture trouble, the fix starts with the water source, then containment and removal as needed.
Find the source
Contain the area
Remove and dry
See emergency mold remediation if you need it.
Frequently Asked Questions
Is mold air testing accurate?
It accurately reports what was in the air during sampling, but air levels change with humidity, weather, and activity. Treat results as a snapshot and interpret them with an inspection and an outdoor comparison.
Do I need mold testing if I can see mold?
Usually not. The EPA says sampling is usually unnecessary when visible mold is present. The mold should be removed and the moisture source fixed.
What is an acceptable mold spore count indoors?
There is no federal standard for acceptable levels. Results are compared with an outdoor sample from the same day. Indoor mold types not found outdoors, or indoor levels well above outdoor levels, may indicate a moisture problem.
Why is an outdoor air sample taken too?
Mold spores are naturally present in outdoor air, so the outdoor sample is the baseline that indoor results are compared to.
Get Mold Air Testing With Laboratory Analysis
MOLD. PNW’s mold air testing uses air sampling and laboratory analysis so you get results in plain language. Related reading: common household molds and top 10 signs of mold.
Our team handles:
Mold inspections and moisture mapping
Mold air testing with laboratory analysis
Crawlspace and attic evaluations
Emergency mold remediation
Mold prevention and protective treatments
Fast action can save your home from extensive mold growth and expensive repairs. Call Us Now: 509.936.3567
Serving: Spokane County, Spokane Valley, Liberty Lake, Post Falls, Rathdrum, Hayden, and Coeur d’Alene
