Using Vacuum Cassettes or Spore Traps to Collect Mold or Particle Dust Samples
How to do it &
Guide to Good Dust Sampling Practices
- VACUUM CASSETTE FILTER SAMPLE TESTS for DUST / MOLD - CONTENTS: Field testing vacuum cassettes to collect building dust as a screen for toxic or allergenic mold contamination indoors. Guide to use of vacuum cassettes to screen building soft surfaces, furniture, carpeting. Guide to use of vacuum cassettes to collect multiple dust samples in buildings
- POST a QUESTION or READ FAQs about using vacuum sampling methods to test for building dust or mold contamination
Vacuum cassette test methods for building dust or mold:
This article explains the advantages and shortcomings of using vacuum cassettes or spore traps to collect mold test samples (or other dust or particle samples) from indoor surfaces such as carpets, couches, or multiple hard surface dust samples
. In this article series 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, beginning with air sampling for airborne mold levels indoors.
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A Guide to Using Vacuum Samples for Screen Buildings for Toxic Mold
15th Annual North Carolina/South Carolina
Environmental Information Association Technical Conference
Myrtle Beach, SC
Daniel Friedman 23 September 2005, Updated 4/14/2009 & 10/5/2012
A collection canister is connected to an air or vacuum pump which is used to
draw particles onto a filter-surface or into a special collection container.
A collection device, slide, cassette, or tape are used with a calibrated air pump to collect surface particles.
The lab prepares a slide from the cassette (of the types below) or if an MCE filter cassette was used to collect particles, the lab clears the filter onto a microscope slide, washes the filter onto a
microscope slide, or uses another method to transfer particles for examination
by microscope for preparation by culture.
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.
Using a simple portable pump calibrated to a known flow rate allows rough estimation of particle density per square inch of surface tested if that analysis is needed.
People using this approach may make use of a disposable paper square template that defines a precise surface area to be vacuumed (photo above left). In our opinion a precise quantitative approach to surface vacuuming is silly because there is normally large particle variation over building surfaces for many reasons. But the approach is useful to screen for high levels of particular particles (such as mold spores, animal dander, insect allergens).
Our photo (left) shows five vacuum test areas on a hallway carpet during a study conducted by the author to examine the variation in particle deposition by foot traffic in a residential hallway.
Our hypothesis was that more outside dirt and debris could always be found in the center of the main path of foot traffic even though that area also received more aggressive vacuum cleaning than the hallway sides. We have tested carpeting before and after various types of cleaning and after suffering various types of contamination.
Surface vacuuming for mold
We emphasize that in this article we are discussing surface vacuuming to collect particles from an exposed surface onto which the vacuum device and collector can be placed directly.
This is an effective and useful particle or mold sampling method.
We are not referring building wall or ceiling cavity vacuuming methods that attempt to draw air and particles from the building cavity through a punctured opening and tube into a collecting device - an approach that our test found was ineffective.
We discuss building cavity vacuuming below at Vacuuming building cavities.
Vacuum samples can be useful for testing soft goods (clothing, bedding,
curtains, carpets) for high levels of contaminated
spores in a qualitative approach. We particularly like vacuuming a number of
surfaces in an area using a single collection device as a less-costly way to
make a more confident inspection of the level of contamination by moldy dust in
buildings with a known problem.
We also use this method as part of a mold
clearance inspection to evaluate the thoroughness of both the containment
system and the general cleaning effort. For example we may collect a sample of
vacuumed surface dust from 10 different surfaces in 5 rooms on a floor of a
home, forming a more broad screen for moldy dust than single tape lifts of
We've found wide variety in levels of mold found growing in or on carpets,
depending on a number of variables including even the level of other dirt
present in the carpeting. Some experts question this measure.
Carpet vacuuming for mold is interesting as a
pre and post remediation baseline data source for areas out of the
remediation/containment area, but for any carpet this method quickly overloads
a particle sampler.
The Burkard personal air sampler (photo at left) can also be used to vacuum particles from surfaces provided that a strong air flow is not required to lift the particles from the surface (this device pumps at 10 lpm).
Shortcomings of surface and carpet vacuuming for mold
- Vacuuming will not collect
identifying structural components of mold as well as tape and will almost
certainly damage or destroy the structures which it collects, imposing
some limits on identification
- Vacuuming will not collect
all of the material on a hard surface (which tape handles well). Particles
which are easily lifted by the airflow into the canister will be
over-represented compared with sticky particles which are adhered to the
This problem is particularly sensitive to the flow rate (LPM)
used. A low-flow rate (1LPM) avoids a sample overload problem (too many
particles, can't read the sample) but may fail to collect or under-collect
certain particles. A high flow rate improves particle pick-up but then
limits the number of sample sites (increasing test cost) in order to avoid
sample overload. We suspect that no vacuum method we have tested could
reliably pull mold or debris reliably from deep inside a heavy upholstered
- Carpet vacuums and some
furniture or drapery vacuums will either be overloaded or restricted to
culture (to which we have already objected).
Continue reading at VACUUMING BUILDING CAVITIES or select a topic from the More Reading links or topic ARTICLE INDEX shown below.
Or see VACUUM SAMPLING EQUIPMENT, DIY
Suggested citation for this web page
VACUUM CASSETTE FILTER SAMPLE TESTS for DUST / MOLD at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.
Green link shows where you are in this article series.
- MOLD CONTAMINATION IN BUILDINGS - home
- AIR CLEANER PURIFIER TYPES
- AIR CONDITIONING SYSTEM ODORS
- AIR POLLUTANTS, COMMON INDOOR
- AIR QUALITY on COMMERCIAL AIRCRAFT
- AIRBORNE PARTICLE ANALYSIS METHODS
- ALLERGEN TESTS for BUILDINGS
- ALLERGENS in BUILDINGS, RECOGNIZING
- ALLERGY & MOLD IAQ PRODUCTS
- BIBLIOGAPHY for ENVIRONMENTAL HEALTH, MOLD, IAQ
- BIOLOGICAL POLLUTANTS
- BOOKSTORE - ENVIRONMENTAL
- CACTUS FUNGI / MOLD
- CAR MOLD CONTAMINATION
- CARPET DUST IDENTIFICATION
- CHAIN OF CUSTODY FORM for ENVIRONMENTAL SAMPLES
- DIRECTORY of MOLD / ENVIRONMENTAL EXPERTS
- DISASTERS: BUILDING INSPECTION & REPAIR - home
- DUST SAMPLING PROCEDURE
- DUST ANALYSIS for FIBERGLASS
- EMERGENCY RESPONSE, IAQ, GAS, MOLD
- FORENSIC & IAQ FIELD IAQ EQUIPMENT SOP - home
- HOUSE DUST ANALYSIS
- HUMIDITY CONTROL & TARGETS INDOORS
- INDOOR AIR QUALITY IMPROVEMENT GUIDE - home
- ITCHY FABRICS
- MILDEW in BUILDINGS ?
- MOISTURE CONTROL in BUILDINGS
- MOLD CONTAMINATION IN BUILDINGS - home
- MOLD: A COMPLETE GUIDE - home
- MOLD / ENVIRONMENTAL EXPERT, HIRE ?
- MOLD TEST PROCEDURES
- MORGELLONS SYNDROME
- MSDS MATERIAL SAFETY DATA SHEETS
- MVOCs & MOLDY MUSTY ODORS
- ODORS GASES SMELLS, DIAGNOSIS & CURE
- OZONE MOLD / ODOR TREATMENT WARNINGS
- PARTICLE & MOLD LEVELS in DUCTWORK
- PARTICLE SIZES & IAQ
- STAIN DIAGNOSIS on BUILDING INTERIORS
- STAINS on INDOOR SURFACES, PHOTO GUIDE
- TECHNICAL & LAB PROCEDURES
- TEST KITS for DUST, MOLD, PARTICLE TESTS
- VAPOR BARRIERS & CONDENSATION
- VENTILATION in BUILDINGS
- VOCs VOLATILE ORGANIC COMPOUNDS
- WATER ENTRY in BUILDINGS
- WORLD TRADE CENTER 9-11 DUST PHOTOS
- FAQs below discusses field reports of problems & solutions for this topic
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Technical Reviewers & References
Publisher's Google+ Page by Daniel Friedman
Click to Show or Hide Citations & References
- 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
- US EPA - Mold Remediation in Schools and Commercial Building [Copy on file at /sickhouse/EPA_Mold_Remediation_in_Schools.pdf ] - US EPA
- US EPA - Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol
- "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
- 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) - The Atlas of Clinical Fungi is also available on CD ROM
- "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,"
Department of Plant Microbiology and Pathology,
Department of Horticulture, University of Missouri Extension - extension.missouri.edu/publications/DisplayPub.aspx?P=G6202
- "Management of Powdery Mildew, Leveillula taurica, in Greenhouse Peppers," Ministry of Agriculture and Lands, British Columbia - Original source: www.agf.gov.bc.ca/cropprot/peppermildew.htm
- Environmental Health & Investigation Bibliography - our own technical library on indoor air quality inspection, testing, laboratory procedures, forensic microscopy, etc.
- Fiberglass: Mold in Fiberglass Insulation© 2005 comments about a field study in process, & more about health hazards from fiberglass insulation - DJF
- 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.
- Fungi, Identifying Filamentous, A Clinical Laboratory Handbook, Guy St-Germain, Richard Summerbell, Star Publishing, 1996, ISBN 0-89863-177-7 (English) (buy at Amazon)
- US EPA: Mold Remediation in Schools and Commercial Building [Copy on file at /sickhouse/EPA_Mold_Remediation_in_Schools.pdf ] - US EPA
- Mycology, Fundamentals of Diagnostic, Fran Fisher, Norma B. Cook, W.B. Saunders Co. 1998, ISBN 0-7216-5006-6 (buy this book at Amazon)
- US EPA: Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol
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