Mold MVOCs, Moldy or Musty Odors, Toxic Mold & Toxic Gas Testing Guide InspectAPedia® -
What are MVOCs and mold smells or musty odors in buildings?
What is the health risk of MVOC exposure?
How to test for and remove MVOCs from buildings.
MVOC detection, & moisture detection as mold detection methods
InspectAPedia offers impartial, unbiased advice without conflicts of interest.
We will block advertisements which we discover or readers inform us are associated with bad business practices,
false-advertising, or junk science. Our contact info is at
InspectAPedia.com/Contact.htm.
This article explains MVOCs or mold volatile organic compounds, what makes MVOCs, the meaning of the presence or absence of moldy smells in buildings, and MVOC testing. This article series lists and compares classes of mold, air, gas, test methods used in indoor air quality investigation
methodology in searching for possible causes of respiratory illness, asthma, immune system disorders, rashes, skin disease, psychological and neurological
disorders, eye infections, or other symptoms which may have a physiological and environmental component.
Sampling for Mold Volatile Organic Compounds - MVOCs and other Mold-Related Gases in Buildings
As we explain below in our comments about mold sniffing dogs, not all molds generate MVOCs, and even molds that do generate MVOC's don't do so all the time. If the humidity, temperature, light, and other factors don't cause a particular MVOC-generating mold to release this gas, you're not going to detect it on the day of the inspection and test. Just later. At MOLD ODORS, MUSTY SMELLS we discuss the variations in the indoor environment that can turn on or turn off mold smells in a building.
Production of toxins and microbial volatile organic compounds (MVOCs) by fungi in an environmental sample is dependent upon many factors, such as the substrate on which mold is growing, relative humidity and temperature in the moldy environment; the relative importance of each of these factors in toxin production is poorly understood.
But it is clear that the level of MVOCs in a building varies widely from none detected to high, even when the genera/species of mold present include MVOC-producing molds. That is, even an MVOC-producing mold species will not always produce detectable odors and gases.
Indoor and outdoor microbial environments are complex, dynamic and transient in nature, and sampling results will change with time. Viability of bacteria and fungi is influenced by environmental conditions such as relative humidity, available nutrients and temperature. Important microbial ecology factors, such as the presence of competing bacteria, fungi, production of anti fungal and antibacterial metabolites, and insects greatly influence viability.
According to a US EPA Mold and Water Damage Study, Some micro-organisms, including molds, also produce characteristic volatile organic compounds (VOCs) or microbial VOCs (mVOCs). Molds also contain substances known as beta glucans; mVOCs and beta glucans might be useful as markers of exposure to molds.
Some molds are capable of producing toxins (sometimes called mycotoxins) under specific environmental conditions, such as competition from other organisms or changes in the moisture or available nutrient supply. Molds capable of producing toxins are popularly known as toxigenic molds; however, use of this term is discouraged because even molds known to produce toxins can grow without producing them (6). Many fungi are capable of toxin production, and different fungi can produce the same toxin.
Where's the mold smell or musty odor problem source? Even if we detect MVOCs, is that the problem mold in the building? If we don't detect MVOC's does that promise there is no problem mold? No.
Toxic or irritating gases such as mold-produced VOC's, MVOC's, or other odors, toxic chemicals, and combustion products can
be important as life-safety concerns may be involved. Unfortunately no single test or tool can detect all possible building contaminants.
We use methods and equipment which can test for common
contaminants. If the identity of a specific contaminant is known in advance we can also test for a very large number of specific contaminant gases in buildings.
We use gas sampling equipment provided by the two most reliable companies
in the world, Draeger-Safety's
detector-tubes and Drager accuro™ bellows pump, the Gastec™ cylinder pump and detector-tube system produced by Gastec or Sensidyne, and we also use Sensidyne's Gilian
air pump.
For broad screening for combustibles and a number of other toxic gases and for leak tracing we also use Amprobe's Tif8850. All of these instruments, their
applications, and sensitivities (minimum detectable limits) for specific gases are described in our Gas Sampling Plan online document.
Our Indoor Gas Sampling Plan for Residential Buildings describes gas testing
procedures, instruments, detection limits, and it lists some of the toxic (or other) indoor gases for which we can test, depending on the building complaint and building conditions.
Health Effects of MVOC Exposure
Depending on individual sensitivity and health, indoor air quality complaints about moldy odors or smells or MVOCs range from none to allergic or asthmatic reaction to complaints of disorientation and neurological effects. Please see MYCOTOXIN EFFECTS of MOLD EXPOSURE.
We distinguish between building related complaints - reports from individuals that an illness appears to be related to spending time in a particular building, and scientific controlled-case studies which have documented certain relationships between exposure to various substances (such as mycotoxins) and illnesses in humans or other animals. Anecdotal evidence associating building related illnesses and mold is often compelling even when the medical research data remain incomplete. See MOLD RELATED ILLNESS GUIDE and MOLD RELATED ILLNESS SYMPTOMS.
Mold Sniffing Dogs as a Building Screen for Mold
Mold sniffing dogs are unreliable, though fun. For details, see INEFFECTIVE MOLD PRODUCTS for an explanation of why mold sniffing dogs make poor mold detectives and why it's not good for them anyway.
There's no doubt that a dog can be trained to smell mold. What is the dog smelling? MVOCs.
Not all molds generate MVOCs, and even molds that do generate MVOC's don't do so all the time. If the humidity, temperature, light, and other factors don't cause a particular MVOC-generating mold to release this gas, you're not going to detect it on the day of the inspection and test. Just later. Even if we detect MVOCs, is that the problem mold in the building?
Beagles are short as dogs go - and are not good at sniffing out MVOC's that telltale a mold problem high in a building wall or in a ceiling.
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
Mold Prevention Strategies and Possible Health Effects in the Aftermath of Hurricanes and Major Floods, by
Mary Brandt, PhD,1 Clive Brown, MBBS,2 Joe Burkhart, MS,3 Nancy Burton, MPH,3 Jean Cox-Ganser, PhD,3 Scott Damon, MAIA,2 Henry Falk, MD,4 Scott Fridkin, MD,1 Paul Garbe, DVM,2 Mike McGeehin, PhD,2 Juliette Morgan, MD,1 Elena Page MD,3 Carol Rao, ScD,1,5 Stephen Redd, MD,2 Tom Sinks, PhD,2 Douglas Trout, MD,3 Kenneth Wallingford, MS,3 David Warnock, PhD,1 David Weissman, MD3
1National Center for Infectious Diseases
2National Center for Environmental Health
3National Institute for Occupational Safety and Health
4Coordinating Center for Environmental Health and Injury Prevention
5Office of Workforce and Career Development
US EPA - original source: cdc.gov/mmwr/preview/mmwrhtml/rr5508a1.htm - this document includes a discussion of MVOCs.
Schleibinger H, Laussmann D, Brattig C, Mangler M, Eis D, Ruden H. Emission patterns and emission rates of MVOC and the possibility for predicting hidden mold damage. Indoor Air 2005;15:98--104.
HHE Report No. HETA-98-0235-2836, North View Elementary School, Eva Hnizeo, PhD., Greg Kullman, PhD, CIH, Peng-Fei Gao, PhD, CIH, June 2001 includes a description of five unique microbial volatile organic compounds (MVOCs) were detected in the basement area during investigation of mold contamination at this elementary school in Clarksburg WV. Orignal source: cdc.gov/niosh/hhe/reports/pdfs/1998-0235-2836.pdf
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.
Mobile View
The Mold Information Center: