Black Mold Testing: Facts, Myths and When to Test
“Is this black mold?” is one of the most common questions we get. The term sounds frightening, and a lot of what’s online is confusing. Here are the facts about black mold testing, and how to find out what is actually growing in your home.
What people mean by “black mold”
When people say “toxic black mold,” they usually mean Stachybotrys chartarum, a greenish-black mold that grows on materials that stay wet for a long time, such as drywall, wood and paper after a leak or flood. But many other common molds, like Cladosporium and Aspergillus, can also look black or dark green.
Myth #1: You can identify mold by its color
You can’t. Color depends on the species, what it’s growing on, its age and the lighting. A black spot could be Stachybotrys, a different mold, or just dirt or soot. The only way to know is to collect a sample and have a lab identify it.
Myth #2: Only black mold matters
Health agencies such as the CDC and EPA advise treating all indoor mold growth the same way: find and fix the moisture problem and clean up the mold, whatever its color or species. Many molds can trigger allergy and asthma symptoms in sensitive people.
Myth #3: Home test kits give you the answer
Settle-plate kits from hardware stores almost always grow something, because mold spores are present in all outdoor and indoor air. Without a proper outdoor comparison sample and lab analysis, those results are very hard to interpret.
How professional black mold testing works
Surface swab test. We swab the suspect spot and the lab identifies which mold types are present. This answers “what is this?”
Indoor air quality test. We sample indoor air and compare it with an outdoor sample. This shows whether spore levels and types inside are unusual, even when the growth is hidden.
All samples go to a third-party accredited lab, and you receive a clear report, usually within 2–5 business days after the samples reach the lab.
What to do while you wait
Don’t scrape, sand or disturb the growth. That spreads spores.
Fix or report any active leak.
Keep indoor humidity below 60% (ideally 30–50%), as the EPA recommends.
Book a black mold test in Los Angeles
Flat pricing: $399 for the first sample, $179 for each additional sample in the same visit. We serve West Hollywood, Beverly Hills, Hollywood, Santa Monica, Culver City and all of Los Angeles County. Call (310) 999-8772 or book online.