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Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
MOLD: A COMPLETE GUIDE to TEST CLEAN PREVENT
AIR CLEANER PURIFIER TYPES
AIR FILTERS for HVAC SYSTEMS
AIR POLLUTANTS, COMMON INDOOR
AIR QUALITY IMPROVEMENT STRATEGIES
ALLERGEN TESTS for BUILDINGS
ANIMAL ALLERGENS / PET DANDER
ANIMAL ODORS IN BUILDINGSS
ATTORNEYS and EXPERT WITNESSES
BIBLIOGAPHY ENVIRONMENTAL HEALTH, MOLD, IAQ
CAR MOLD CONTAMINATION
CARPET DUST IDENTIFICATION
CARPET MOLD CONTAMINATION
CAT DANDER in BUILDINGS
COMBUSTION GASES & PARTICLE HAZARDS
CONDENSATION or SWEATING PIPES, TANKS
CPSC Indoor Air Pollution Book Online Copy
DUCT SYSTEM & DUCT DEFECTS
EMERGENCY RESPONSE, IAQ, GAS, MOLD
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOODS IN BUILDINGS-mold
GAS EXPOSURE EFFECTS, TOXIC
HUMIDITY CONTROL & TARGETS INDOORS
HOUSE DUST ANALYSIS
HOUSE DUST COMPONENTS
INDOOR AIR QUALITY IMPROVEMENT GUIDE
MILDEW REMOVAL & PREVENTION
MOISTURE CONTROL in BUILDINGS
MOLD GROWTH on SURFACES, TABLE OF
MYCOPHOBIA, STAINS MISTAKEN for MOLD
NOISE / SOUND DIAGNOSIS & CURE
ODORS GASES SMELLS, DIAGNOSIS & CURES
OZONE for MOLD OR ODORS
RADON HAZARD TESTS & MITIGATION
SAFETY HAZARDS GUIDE
SICK HOUSE IAQ QUESTIONNAIRE
SMELL PATCH TEST to Track Down Odors
STAIN DIAGNOSIS on BUILDING INTERIORS
VENTILATION in BUILDINGS
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. Because mold test validity and mold test accuracy are often confused, readers should also see ACCURACY OF VARIOUS MOLD TEST METHODS. People who need to conduct mold inspection and testing indoors should see MOLD TEST PROCEDURES and TECHNICAL & LAB PROCEDURES
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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.
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.
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 surface dust.
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).
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