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ENVIRONMENTAL HAZARDS - INSPECT, TEST, REMEDY
MOLD: A COMPLETE GUIDE to TEST CLEAN PREVENT
ACCEPTABLE MOLD LEVEL
ACCURACY OF VARIOUS MOLD TEST METHODS
ACCURACY vs PRECISION of MEASUREMENTS
ACTION GUIDE - WHAT TO DO ABOUT INDOOR MOLD
ACTIVITY of MOLD in BUILDINGS
AGE of MOLD - Old is the Mold?
AIR CLEANER PURIFIER TYPES
AIR FILTERS for HVAC SYSTEMS
AIR POLLUTANTS, COMMON INDOOR
AIR TEST FOR MOLD: ACCURACY
AIR TEST SAMPLING CASSETTE STUDY
AIRBORNE MOLD COUNT NUMBER GUIDE
AIRBORNE PARTICLE ANALYSIS METHODS
ALLERGEN TESTS for BUILDINGS
ALLERGENS in BUILDINGS, RECOGNIZING
ALLERGY & MOLD IAQ PRODUCTS
ALLERGY TESTS for PEOPLE
ALLERGY TEST ACCURACY
ATTORNEYS and EXPERT WITNESSES
BASEMENT MOLD WATER IMPACT
BROWN HAIRY BATHROOM MOLD
BIBLIOGAPHY for ENVIRONMENTAL HEALTH, MOLD, IAQ
BOD WASTEWATER TEST
BLACK MOLD, HARMLESS COSMETIC
BLACK MOLD, TOXIC & ALLERGENIC
BLEACHING MOLD, Advice about
BLUE vs YELLOW COMBUSTION FLAMES
BOOK MOLD, Moldy Book Cleaning
BOOKSTORE - ENVIRONMENTAL
CACTUS FUNGI / MOLD
CAR MOLD CONTAMINATION
CARPET DUST IDENTIFICATION
CARPET MOLD CONTAMINATION
CARPET PADDING ASBESTOS, MOLD, ODORS
CARPET FUNGICIDAL SPRAY
CARPET STAIN DIAGNOSIS
CARPET & other STAIN TESTS
CARPET TEST PROCEDURE
CARPETING & INDOOR AIR QUALITY
CHAIN OF CUSTODY - TEST SAMPLE
CLEARANCE INSPECTIONS - MOLD CLEANUP
DIRECTORY of MOLD / ENVIRONMENTAL EXPERTS
DIRT FLOOR MOLD CONTAMINATION
Disinfecting Buildings with Bleach
DO-IT-YOURSELF MOLD CLEANUP WARNINGS
DUCT SYSTEM & DUCT DEFECTS
DUST ANALYSIS for FIBERGLASS
DUST, HVAC CONTAMINATION STUDY
DUST SAMPLING PROCEDURE
EFFLORESCENCE, Salts & White / Brown Deposits
EMERGENCY RESPONSE, IAQ, GAS, MOLD
FEAR of MOLD - MYCOPHOBIA
Fiberboard Insulation Sheathing Mold
FIBERGLASS INSULATION MOLD
FIBERGLASS PARTICLE CONTAMINATION TEST
FIELD INVESTIGATION SERVICE
FIND MOLD, ESSENTIAL STEPS
FIND MOLD in BUILDINGS, HOW TO
FIRE DAMAGE vs MOLD DAMAGE
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOODS IN BUILDINGS-mold
FLOORING MATERIALS, Age, Types
FOXING STAINS on books & papers
FUNGICIDAL SPRAY & SEALANT USE GUIDE
GAS DETECTION INSTRUMENTS
GAS EXPOSURE EFFECTS, TOXIC
GAS EXPOSURE LIMITS & STANDARDS
GAS TEST PROCEDURES
HOUSE DUST ANALYSIS
HOUSEWRAP AIR & VAPOR BARRIERS
HIDDEN MOLD, HOW TO FIND
HUMIDITY CONTROL & TARGETS INDOORS
INDOOR AIR HAZARDS TABLE
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INDOOR AIR QUALITY IMPROVEMENT GUIDE
LAB PROCEDURES MICROSCOPE TECHNIQUES
LEAD POISONING HAZARDS GUIDE
Legionella Legionnaires' Disease
Legionella BACTERIA & HVAC Equipment
LIGHT, GUIDE to FORENSIC USE
LP & Natural Gas Safety Hazards
MEDIA BLASTING for MOLD REMOVAL
METHANE GAS SOURCES
MICROSCOPE DIGITAL PHOTOGRAPHY
MEDIA BLASTING for MOLD REMOVAL
METHANE GAS SOURCES
MICROSCOPE DIGITAL PHOTOGRAPHY
MILDEW in BUILDINGS ?
MILDEW ERRORS - MOLD PHOTOS
MILDEW REMOVAL & PREVENTION
MOISTURE CONTROL in BUILDINGS
MOLD: A COMPLETE GUIDE TO MOLD
MOLD ACTION GUIDE - WHAT TO DO ABOUT MOLD
MOLD APPEARANCE - WHAT MOLD LOOKS LIKE
MOLD CLEANERS - WHAT TO USE
MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD
MOLD CLEARANCE INSPECTIONS
MOLD COUNT NUMBER GUIDE
MOLD CONSULTANTS / INSPECTORS
MOLD CULTURE TEST KIT VALIDITY
MOLD DETECTION & INSPECTION GUIDE
MOLD or INDOOR AIR EMERGENCY RESPONSE
MOLD EXPERT, WHEN TO HIRE
MOLD LEVEL IN AIR, VALIDITY
MOLD ODORS, MUSTY SMELLS
MOLD PREVENTION GUIDE
MOLD RELATED ILLNESS GUIDE
MOLD SAFETY WARNINGS
MOLD SPRAYS, SEALANTS, PAINTS
MOLD TEST KITS
MOLD TESTING METHOD VALIDITY
MSDS Material Safety Data Sheets
MVOCs & MOLDY MUSTY ODORS
MYCOPHOBIA, STAINS MISTAKEN for MOLD
MYCOTOXIN EFFECTS of MOLD EXPOSURE
NOISE / SOUND DIAGNOSIS & CURE
ODORS GASES SMELLS, DIAGNOSIS & CURE
OZONE for MOLD OR ODORS
PAINTS & COATINGS ODORS IN BUILDINGS
PARTICLE SIZES & IAQ
Particulates & Allergens Indoors
Pesticide Exposure Hazards
PET ALLERGEN REMEDIES
PLASTIC CONTAINERS, TANKS, TYPES
PLASTIC HEATER VENT
PLASTIC ODORS-SCREENS, SIDING
PLUMBING SYSTEM ODORS
RENTERS GUIDE TO MOLD & IAQ
ROBIGUS & Wheat Rust Fungus
ROT RESISTANT LUMBER
ROT, TIMBER FRAME
ROT, TIMBER ASSESSMENT
SLIDE PREPARATION, MICROSCOPE
SMELL PATCH TEST to Track Down Odors
SOUND CONTROL in BUILDINGS
STAIN & BIODETERIORATION AGENT CATALOG
STAINS on & in BUILDINGS, CAUSES & CURES
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on BUILDING INTERIORS
STAINS on INDOOR SURFACES: PHOTO GUIDE
STAINS & Thermal Tracking
TECHNICAL & LAB PROCEDURES
TEST KITS for DUST, MOLD, PARTICLE TESTS
Thermal Expansion Cracking of Brick
THERMAL EXPANSION of HOT WATER
THERMAL EXPANSION of MATERIALS
THERMAL IMAGING, THERMOGRAPHY
THERMAL IMAGING MOLD SCANS
THERMAL MASS in BUILDINGS
THERMAL TRACKING & THERMAL BRIDGING
TRAPPED MOLD BETWEEN WOOD SURFACES
TRIM, INTERIOR INSTALLATION
TRAPPED MOLD BETWEEN WOOD SURFACES
TRUSS UPLIFT, ROOF
TRUSSES, Floor & Roof
Urea Formaldehyde Foam Insulation UFFI
URETHANE FOAM Deterioration, Outgassing
UV LIGHT BLACK LIGHT USES
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
VINYL CHLORIDE HEALTH INFO
VINYL Siding or PLASTIC Window ODORS
Volatile Organic Compounds VOCs
WALL SIDING TRIM & FINISHES
WALL FINISHES INTERIOR
WALL CONSTRUCTION BARRIER vs CAVITY
WATER BARRIERS, EXTERIOR BUILDING
WATER ENTRY in buildings
WATER ODORS, CAUSE CURE
Mold killing guide: this document explains a very common mistake in mold cleanup jobs: relying on bleach, biocides, or fungicides to "kill" toxic mold. This is a chapter of the Mold Action Guide, a document which provides an easy to understand step-by-step guide for dealing with toxic or allergenic indoor mold and other indoor contaminants: what to do about mold. The steps in this article series will be sufficient for many building owners who want to do their own mold investigation, mold testing, mold cleanup, and mold prevention in their home or office.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Many readers have contacted us to ask about using bleach, fungicides, or biocides as a "mold remediation" step and many mold remediation projects we've seen have placed too much reliance on attempts to spray or gas mold to try to "kill the mold and render it harmless" that we've added this brief article on what's "right" and "wrong" about relying on any spray, gas, chemical, or "treatment" to treat problem mold in buildings.
Here is what the U.S. EPA says about using biocides, bleach, mold killers, mildewcides:
Spraying, Bleaching, or Killing Mold Does Not Kill All of the Spores
First of all, after spraying or gassing "toxic mold" or "black mold" in a building, the bad truth is that the mold is not dead - at least not all of it. Even if you spray bleach all over your "black toxic mold" you won't kill every single spore. I've examined bleached mold samples in the lab. I can usually tease out viable spores from the supposedly "dead" mold sample. To kill every single mold spore using bleach, for example, you'd have to use such a high concentration of disinfectant and you'd have to keep it on the surface for so long that more likely you'd damage the structure - and still miss some toxic spores.
This is particularly true when people rely on spraying rather than physically cleaning or removing moldy surfaces or materials.
To be scrupulously fair, if we sprayed a surface with sufficient force as to actually physically clean it (and if we removed all of the sprayed-on liquid and debris, we'd do a credible job of cleaning the surface of problem mold. Of course in fact, you could use water or deck cleaner or a dry product like baking soda for such purposes just as well as a disinfectant. See our Report on Media Blasting for an example of using a "spray" approach to physically clean a surface.
- Thanks to Arlene Puentes for technical edits.
Killing Mold Spores Leaves Toxic or Allergenic Particles in Place
Second - even if in theory we could "kill" every spore, the assumption that they are unimportant is highly questionable. "Dead" spores often contain allergens or toxins that are just as harmful to someone breathing them or getting such mold in one's eye or in a cut, as before.
Relying on Mold Sprays, Bleach, Biocides, Fungicides Risks Taking an Ineffective "Short Cut" to Mold Removal
Third - when I hear remediators or testers focused on whether mold is "alive" or "dead" we are immediately concerned that they do not understand the best practices regarding mold problem diagnosis and cure.
The object is not to "kill" mold, it is - to remove the mold reservoir in the building by physical cleaning or in cases of items that can't be cleaned, such as drywall, soft goods, carpets, furniture, or insulation, remove the moldy material - to identify the cause and make sure that's been corrected (which in your case you think has been done but I'm doubtful where a crawl space is involved - wet conditions that made part of a building wet have often affected other building areas that are less obvious).
It is Important to Find, Identify, and Remove All of the Problem Mold Reservoirs in a Building
Fourth and very important - we need to be very confident that ALL of the substantial mold reservoirs at a building have been identified and cleaned-up or removed.
My experience is that very often people focus too quickly on the mold that they see, say on wood in a crawl space, and fail to detect an as large or larger and as problematic or more harmful mold reservoir that they didn't "see". Examples of this mold killer approach error include:
Hire a Competent Professional for a Thorough Visual Inspection for Problem Mold and Its Causes
SO what you need (and might already have) is great confidence that the expertise of the mold or building inspector and the scope of the investigation have been very accurate and thorough before any remediation project is begun. Otherwise the risk is that you have to repeat the process again later.
Even if you clean or remove problem mold thoroughly, if you do not correct the original cause of mold growth, you are likely to face this trouble and cost all over again.
How Should Small Areas of Mold be Handled?
Small Areas of mold: clean and disinfect surfaces: small areas of mold (less than 10 sq.ft. or less than 30 sq.ft. in some guidelines)can be cleaned by most property owners using common household cleaners or simple soap and water; if using bleach, extra caution is in order.
While demolition/removal of building components in of small areas of mold may not be required, in some cases removal/replacement of moldy materials permits valuable additional investigation for hidden mold, and may be easier than cleanup, particularly where surfaces or materials are in poor condition or where mold is on drywall or other components such as fiberglass insulation or duct work which can't be cleaned. If further investigation, renovation or repair discloses mold or conditions which cause growth of large areas of mold, professional cleanup/removal by an expert remediator would be needed.
How Should Large Areas of Toxic or Allergenic Mold be Handled?
Large areas of mold (more than 30 sq.ft. of contiguous problem mold): professional cleanup is needed by an expert remediator and is likely to involve significant expense. "Large" is more than 10 sq.ft. according to the US EPA, or 30 sq.ft. per the NY City Guidelines. For instructions for remediation see the NY City guidelines at http://InspectAPedia.com/sickhouse.htm#action. If your remediator is not familiar with these guidelines s/he may not be properly informed to do the job.
What Good is Bleach in a Mold Remediation Project?
Though normally weI do not enthuse about "bleaching" mold (since leaving a dead mold spore in place can still be harmful and can leave toxins), careful cleaning of otherwise already HEPA-vacuumed debris-free surfaces with a proper bleach solution (5%) is an effective end measure for hard surfaces - not much use on upholstered furnishings. .
Watch out: do not accept a mold remediation job that relies principally on bleaching surfaces. The mold reservoir needs to be found, removed, its cause corrected, and all related surfaces cleaned (or non-cleanable materials thrown out). Then using a biocide, sanitizer, or bleach solution for final cleaning is ok provided the solution is used according to the manufacturer's directions and applied safely.
Frequently Asked Questions (FAQs)
Questions about how killing or destroying mold or mold growth in or on buildings.
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