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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 or URINE ODOR SOURCE DETECTION S
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 MOLD / ODOR TREATMENT WARNINGS
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 tests on building insulation to screen for mold or other particles: 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 building insulation where mold, insect, or other contamination is suspected.
Our photo (page top) shows what looked like clean fiberglass insulation located over a basement that had been subject to chronic flooding and ultimately, mold contamination that was visible on other basement surfaces. Vacuum tests confirmed that the insulation contained high levels of Penicillium/Aspergillus mold spores and was acting as a mold reservoir in the building.
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At many investigations we have found a large hidden mold reservoir in building insulation, particularly fiberglass insulation in attics under roof leaks over drywall, and in crawl spaces which have been damp or wet. We have also found very moldy fiberglass in basement ceilings after moldy surfaces and debris have been removed (such insulation should have been removed during the remediation).
[Click to enlarge any image]
Our photo (left) shows insulation that did not display visible mold but that our vacuum test found to be very mold-contaminated (see our lab photo below). (The dark stains on this fiberglass insulation were not mold but house dust deposited from air movement - see THERMAL TRACKING & THERMAL BRIDGING for details.)
Our method is to agitate the target insulation (simply poke it with your flashlight or a ruler), followed by holding our vacuum cassette an inch or two away from the insulation surface. This reliably picks up particles from the insulation without overloading the sample with fiberglass. (A baseline comparison sample collected in nearby building air before any such agitating sampling is also needed.) This method has been remarkably successful in finding and allowing the removal of several "mystery" problems in buildings where severe mold-related complaints were heard.
Any of several types of vacuum cassettes are used to collect dust from a surface. We use Air-o-Cel ™ cassettes and MCE filter cassettes. We am experimenting with vacuum cassettes loaded with high-adhesive tape.
The contents of the mold test vacuum cassette may be examined by light microscope or may be used for preparation of cultures. One special (and costly) cassette method collects dual samples permitting both direct examination and culturing.
Our lab photo (left) shows insulation that did not display visible mold to the naked eye when examined in place in the building (photo above) but that our vacuum test found to be very mold-contaminated.
This method may be used for both qualitative and quantitative analysis, depending on collection method details. It is best suited for sampling dust from surfaces and from soft goods such as carpeting or upholstered furniture.
It's strength is its use in examining multiple hard surfaces with relatively low levels of debris (avoiding sample overload) or individual soft surfaces where tape may not collect particles imbedded in the surface, and in collecting dust from multiple locations in a single cassette as a building dust scan for mold.
We love this method, but one must take care not to overload the sample.
If insulation is not exposed for testing one needs to make a sufficiently large opening to agitate and then vacuum the insulation - we use a 4" square opening and take care to avoid vacuuming up simply a collection of drywall dust.
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.
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.
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