Using Adhesive Tape to Collect Mold Samples: Guide to Good Practices InspectAPedia® -
How to collect building dust, debris, or particles for identification using clear adhesive tape
How to use adhesive tape for mold identification samples
How to use adhesive tape to screen building dust for mold or other particulate contaminants
Use of adhesive tape to trace building dust particles to their source
Why is tape sampling preferred during building air quality or mold investigations?
Limitations of tape sampling for mold or other building particles
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This article explains the advantages and shortcomings of using adhesive tape to collect mold test samples (or virtually any other other dust or particle samples) from indoor surfaces. In this article series we discuss the validity of nearly all of the popular mold testing methods currently in use, pointing out the strengths and weakness of each approach to mold sampling in the indoor environment.
This study presents a summary and critique of some popular methods used to examine indoor air quality to test for presence or absence of problematic levels of toxic or allergenic mold or other bioaerosols. Our page top photo demonstrates that the tape sampling location is critical for accurate identification of particles or mold types in a building - each of the three tapes in this photograph collected an entirely different genera/species of mold. We describe and critique specific "testing" or "sampling" methods used to
"test" buildings for mold in the course of a building investigation. The appropriateness of testing at all is discussed on this and other pages at
our website.
At MOLD TEST KITS for DIY MOLD TESTS we provide a detailed, step by step guide to using clear adhesive tape to collect particles from building surfaces to test a building for a history of exposure to airborne (and dust) presence of allergens, animals (dogs, cats, mice, rats, others), asbestos, cockroaches, dust mites, fiberglass, insect fragments, pollen, soot, or mold. Building dust samples can also be used to trace dust or problem particles to their source, such as insulation from damaged duct work, or in some cases, failing HVAC equipment.
Our MOLD INFORMATION CENTER includes more broad discussions of the overall approach to building investigation, as do many expert references cited at that web. For a more
comprehensive collection information about mold test methods see INDOOR AIR QUALITY METHODS COMPARED.
For more on "mold classes" (Cosmetic mold vs. allergenic mold vs. toxic or pathogenic mold) see MOLD CLASSES, HAZARD LEVELS and more references such as a Mold Action Guide are at the end of this document.
Recommendations for Using Tape sampling for Testing Buildings for Toxic Black (or other) Mold
15th Annual North Carolina/South Carolina
Environmental Information Association Technical Conference
Myrtle Beach, SC
Daniel Friedman 23 September 2005, Updated 4/14/2009
Clear cellophane tape is pressed into a sampled surface, then removed and
affixed to a clean surface such as a plastic bag or a microscope slide for
mailing to a lab. The lab prepares the tape for microscopic examination. For
mold genera and species identification the tape is examined in the laboratory.
Tape samples can also be cultured (see Culture discussion below). This is the
least-expensive collection method available, and is a preferred tool.
Using clear adhesive tape pressed into a surface to be tested is the first
choice recommended method for identifying mold in a building, particularly when
combined with visual inspection as part of a mold investigation, per AIHA and
other expert sources. This method permits rapid identification of genera
(family name) and very often species (individual member name), particularly
when the mold sampled has uniquely-identifiable spores or where the sample
collects the conidiophore or spore-producing body as well.
In some cases genera determination alone is quite sufficient as the some of
the common problem-genera (Penicillium sp. and Aspergillus sp.)
do not have non-problematic members which grow in buildings. Speciation is more
likely to be needed when doing medical diagnosis. Tape samples can also be
cultured if additional speciation is needed. Since tapes can collect the
conidiophores and hyphae (when tape spot is chosen with some thought) they give
more data than an air or vacuum sample.
For building where large amounts of mold are found or suspected, tape
sampling is a qualitative approach which is usually quite successful in
addressing the basic question: is there a problematic genera which requires
professional remediation? Combined with a visual inspection to locate target
areas of risk and to find visible problems, it is the most essential component
of a building mold investigation and is the method recommended by experts
writing in the field and by the AIHA's own training materials.
Tape samples are the preferred method of collecting surface samples in
buildings. Tape pressed into appropriate portions of suspected mold growing on
a surface collects the most material from the surface and often includes
sufficient structural material to identify the dominant problematic genera and
species present.
A properly collected sample is likely to contain both fungal
conidia, conidiophores, and hyphae, the latter two of which are important aids
for speciation. Tape samples of building dust and even tape samples of moldy
carpet are also generally useful in this manner but have some limitations
discussed below.
A Guide to Using Tape Sampling for Determination of Mold genera and Mold species:
Nearly all building mold genera can be determined by light microscopic
examination of tape samples. In the majority of building investigation cases
the key question is "is there a problematic genera (toxic or allergenic)
requiring containment and professional remediation?"
This can almost
always be completely answered from genera alone. This is because within the
more common troublemakers, their non-problematic member species may not occur
in buildings. For example, Penicillium notatum, used for the drug penicillin,
does not grow in buildings! If you find Penicillium sp. in a building in
quantity it needs to be remediated.
Speciation of many mold genera can also be determined from tape sample
material alone in many but certainly not 100% of cases. Some examples of easily
speciated molds from among the most common genera and species found in
buildings: Cladosporium sphaerospermum,
C. cladosporioides, Ulocladium chartarum, Taeoniella rudus, Pithomyces
chartarum, Stachybotrys chartarum, Chaetomium globosum, Chaetomium aureum,
Aspergillus niger are just a few examples.
Our photo (left) shows a nicely preserved conidiophore of Aspergillus niger on an adhesive tape sample.
A good mold tape sample which collects the conidiophore and
hyphae makes speciation possible for many molds. Many other airborne spores
appear in buildings and can be similarly speciated, but are not building molds.
Other airborne molds such as the Aspergillus and Penicillium families are probably
a sufficient hazard in buildings that if they are present in a large reservoir,
speciation is not needed to decide to remediate.
Shortcomings of tape sampling tests for Toxic Mold:
Everything depends on where
you stick the tape. Investigators and ordinary building occupants tend to
collect that which is easy to see - "black mold" and may miss more
important, more health-risky light-colored and highly airborne genera
(Aspergillus, Penicillium) which are also present but more difficult to
see. An expert looks for mold-suspect material that seems to represent the
dominant presence in an area by color, texture, and growing surface
material. It would be unusual for there to be only a single genera/species
of mold in a mold-problem building. Looking and taping requires some
guidance and education.
Some smaller airborne mold
spores do not settle out of air rapidly and might appear equally as
plated-out on walls as in dust on horizontal surfaces. In building
inspection to search for an unidentified problem source, samples of
surface dust may under-represent the presence of these molds, though where
a substantial airborne presence exists we have always found a surface dust
presence as well. By contrast, properly collected tape samples from
visible mold growing on a surface does not suffer this shortcoming.
Speciation of genera may be
needed for special medical diagnostic reasons. From spores alone in any
sample method, two of the most widespread problematic genera can be
speciated only to a few cases. (Aspergillus
niger for example.) Therefore
for medical use, tape speciation of some genera is too limited, in
particular if the sample collects only spores - a problem which can occur
if tape is pressed into dust rather than into an area of growing mold, or
when tape of a mold colony is pressed into a spore-packed center of a
mature colony instead at the edges where the new colony growth and
conidiophores are easier to find. A little knowledge of mycology is useful
to professional building inspectors.
When growing conditions
become unfavorable some molds change form into an encysted or encapsulated
dormant state, forming fungal perithecia, cleistothecia, or pycnidia which
may be collected as "black stuff" from building surfaces
(particularly wood). While often one finds identifiable material among
perithecia that cant' be assured. Culturing of such samples may produce an
identifiable fungus if by luck the right culture media is selected.
Tape sampling is qualitative,
not quantitative. Most experts and competent labs will offer a description
of the density of fungal material found in the sample using
non-standardized terms like Level 1-2-3-4 or Light, Medium, Heavy, or
Dominant, Present, and Incidental. These terms lack a standard definition
but are of some use provided the lab has and can provide their own
standard and definition.
In sum, the determination of the presence of a building mold problem (toxic
or allergenic) vs. cosmetic mold can usually be made from tape samples alone. Tape samples are preferred by the most experienced and trained professionals in the aerobiology field.
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Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211 mark@BestTampaInspector.com
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
Kansas State University, department of plant pathology, extension plant pathology web page on wheat rust fungus: see http://www.oznet.ksu.edu/path-ext/factSheets/Wheat/Wheat%20Leaf%20Rust.asp
"A Brief Guide to Mold, Moisture, and Your Home",
U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
Allergen Tests in Buildings advice about how to test, what to look for, in evaluating the level of dog, cat, or other animal allergens in a building
"IgG Food Allergy Testing by ELISA/EIA, What do they really tell us?" Sheryl B. Miller, MT (ASCP), PhD, Clinical Laboratory Director, Bastyr University Natural Health Clinic - ELISA testing accuracy: Here is an example of Miller's critique of ELISA
http://www.betterhealthusa.com/public/282.cfm - Townsend Letter for Doctors and Patients
The critique included in that article raises compelling questions about IgG testing assays, which prompts our interest in actually screening for the presence of high levels of particles that could carry allergens - dog dander or cat dander in the case at hand.
http://www.tldp.com/issue/174/IgG%20Food%20Allergy.html contains similar criticism in another venue but interestingly by the same author, Sheryl Miller. Sheryl Miller, MT (ASCP), PhD, is an Immunologist and Associate Professor of Basic and Medical Sciences at Bastyr University in Bothell, Washington. She is also the Laboratory Director of the Bastyr Natural Health Clinic Laboratory.
Allergens: Testing for the level of exposure to animal allergens is discussed at http://www.animalhealthchannel.com/animalallergy/diagnosis.shtml (lab animal exposure study is interesting because it involves a higher exposure level in some cases
Allergens: WebMD discusses allergy tests for humans at webmd.com/allergies/allergy-tests
Animal Allergens: Dog, Cat, and Other Animal Dander - Cleanup & Prevention Information for Asthmatics and regarding Indoor Air Quality.
Recognizing Allergens: What various indoor allergens look like - identification photos to help identify pollen, dust mites, animal dander, toxic or allergenic mold - Common Mold and other Allergens, Irritants, Remedies & Advice
Rodent control issues, including dander, fecal, and urine contamination of Buildings and Building insulation are discussed at our
Associations: Sick House, Sick Building, SBS - Air Quality, Government, Private Associations and Information Resources
Atlas of Clinical Fungi, 2nd Ed., GS deHoog, J Guarro, J Gene, & MJ Figueras, Centraalbureau voor Schimmelcultures, Universitat Rovira I Virgili, 2000, ISBN 90-70351-43-9 (you can buy this book at Amazon)
Atlas of Indoor Mold, Online Clinical Mold Atlas, Toxins, Pathogens, Allergens and Other Indoor Particles - Medical Health Effects of Mold (separate online document)
Black Mold that is Harmless Photos of recognizable, usually harmless black mold on wood, bluestain, ceratocystis, ophistoma
Building Floods: quick steps after a building flood or plumbing leak can prevent costly mold contamination
Classes of Mold: what types of cosmetic, allergenic, or toxic mold are a problem? Can mold be cleaned-up successfully?
"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
"Disease Prevention Program for Certain Vegetable Crops," David B. Langston, Jr., Extension Plant Pathologist - Vegetables, University of Georgia (PDF document) original source: www.reeis.usda.gov/web/crisprojectpages/209797.html
"Disease Prevention in Home Vegetable Gardens,"
Patricia Donald,
Department of Plant Microbiology and Pathology,
Lewis Jett
Department of Horticulture, University of Missouri Extension - extension.missouri.edu/publications/DisplayPub.aspx?P=G6202
Fifth Kingdom, Bryce Kendrick, ISBN13: 9781585100224, is available from the InspectAPedia online bookstore - we recommend the CD-ROM version of this book. This 3rd/edition is a compact but comprehensive encyclopedia of all things mycological. Every aspect of the fungi, from aflatoxin to zppspores, with an accessible blend of verve and wit. The 24 chapters are filled with up-to-date information of classification, yeast, lichens, spore dispersal, allergies, ecology, genetics, plant pathology, predatory fungi, biological control, mutualistic symbioses with animals and plants, fungi as food, food spoilage and mycotoxins.
OTHER IAQ ISSUES: How To Find and Address Other Indoor Air or Indoor Environment Contaminants Besides Mold
Mold or allergens may not be the only or even the main indoor environmental contaminant. Don't let media attention to mold
cause so much enviro-scare fear that other, possibly more urgent hazards go un-addressed.
Ozone Warnings - Use of Ozone as a "mold"
remedy is ineffective and may be dangerous.
Pet control - if you can't say goodbye to your bird, cat, dog, guinea pig, hamster, tropical fish, then limit the
areas they occupy and limit the airflow from that area to sleeping or other areas of the building, use allergenic
bedding, eliminate wall-to-wall carpeting, improve housecleaning including use of a HEPA-rated vacuum cleaner. For more details
see our article Dog, Cat, and Other Animal Dander - Information for Asthmatics and Indoor Air Quality
Rodents, Mice, Squirrel Control - I find high levels of mouse and rodent dander, fecal dust, and urine-contaminated dust in some buildings,
and high levels of these materials in building insulation in those locations. If you have a mouse problem, particularly if mice and their waste (fecals or urine) are contaminating
the building HVAC or building insulation, may need both steps to clean up or remove infected materials and steps to stop an ongoing
rodent problem. If squirrels are a problem, the cleanup needs to include closing off entry openings into the building. Get some
help from a licensed pest control expert.
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