Mold Species Identification
How to Collect Bulk Physical Mold Growth Samples for
Low-Cost Mold Laboratory Identification of Mold Species
Many property owners, apartment landlords, renters, employers, and
employees want to know, and need to know, the precise identities of the
various mold species infesting their moldy house, rental unit, or place of
employment, according to Phillip Fry,
Mold Inspector and author of the mold book
Mold Prevention, Inspection, Testing, & Remediation.
The accurate mold laboratory identification of mold
species requires two steps: (1) physical collection of mold samples from
the moldy building; and (2) mold laboratory analysis of the collected mold
The least costly way to collect mold samples is the do-it-yourself approach
carried out by gathering actual samples of mold growth to submit the
collected mold samples to a mold lab [many on the internet].
Bulk Physical Mold
Sampling Mold Lab Analysis
If a property owner or occupant sees mold growing on a wall, ceiling, floor,
heating or cooling duct register, or any other surface, he can scrape mold
particles off the mold growth area into a small ziplock bag. Collecting such
a physical sample is “bulk mold sampling” or “physical mold sampling.”
During such scraping of the mold growth, the tester needs to wear rubber
gloves and a full-face respirator mask with organic vapor filters (such as
the 3M brand from a large hardware, home improvement, or safety store).
do the scraping, use a new or thoroughly disinfected (with ethyl or rubbing
alcohol) paint scraper. Disinfect the scraper after each individual sampling
to remove any possible mold contaminants, and thus avoid mold
cross-contamination in the sampling process from one source or location to
What should be the minimum bulk physical sample size? At least 25 -
50 grams of a bulk physical sample should be submitted to the the mold
the total submitted sample, approximately 10 grams will be inoculated into a
mold culture plate [petri dish containing agar food nutrient for the mold
spores to eat] to watch for mold growth over a 7 day period prior to mold
analysis and mold species identification.
Print clearly and neatly on a large pressure sensitive label the property
owner’s name, the property address, the precise test location at that
address, the testing date, and the type of sampling method (“bulk sample”),
along with the tester’s name and contact information.
The label should also include each individual test number, as listed on the
mold chain of custody form, available free from the mold laboratory. Attach
the label to the ziplock bag containing that respective, numbered mold
Alternatively, the tester can scrape the mold particles directly into a mold
test kit (Petri dish) to start the growing (“culturing”) of the mold sample.
This “viable testing” growth process takes 5 to 7 days for accuracy in mold
The tester can then either watch the test kits for mold growth, or send the
mold test kit to the mold lab immediately, or after the self-observation
Another bulk physical sampling technique is to cut out a small section (no
larger than 2 inches by 2 inches) of a building material or home furnishing
that contains significant mold growth. Then, put that cut piece into a small
ziplock bag, or press firmly the moldy side down into a mold test kit.
Follow the same labeling instructions explained above. Then mail or deliver
your physical bulk samples to the mold laboratory.
Examples of moldy materials from which bulk samples can be cut for mold lab
analysis are wood timbers, drywall, plasterboard, wallpaper, ceiling tile,
carpeting, padding, heating/cooling system filters, clothing, furniture
upholstery, and any other favorite mold food.
Tape Lift Sampling
The easy steps involved in tape lift sampling to collect physical bulk
mold samples are---
1. Cut a three-inch (3”) long strip of one-inch (1”) wide, transparent
sticky tape, such as Scotch® Brand Tape.
2. While wearing rubber gloves and a breathing respirator mask (with organic
vapor filters) from the local hardware or home improvement store, press the
tape strip firmly (sticky side down) onto the visible mold growth or onto
the surface being tested.
3. Remove (peel back) the tape from the surface.
4. Open up a small ziplock bag (a transparent, easily sealable plastic
storage bag), and press lightly the lift tape sample sticky side onto the
inside sidewall of the ziplock bag.
5. Close [zip shut] the ziplock bag completely. Tape it shut if necessary to
make sure no airborne mold spores can escape.
6. Attach to the outside of the ziplock bag a large adhesive label with the
same types of sample identification information specified above, except that
the type of sampling method is “lift tape sampling.” Then mail or deliver
your lift tape samples to the mold laboratory.
For more information about bulk physical mold sampling,
lift tape mold
sampling, mold laboratory analysis, mold species identification, and
mold species identification, please