Formaldehyde Gas & Outgassing Hazards In buildings InspectAPedia® -
Table of sources of formaldehyde gas or odors in buildings
Formaldehyde gas exposure limits
How to reduce formaldehyde exposure levels in a building
Current sources of formaldehyde gas concerns in buildings
Formaldehyde outgassing health concerns in FEMA trailers provided as temporary housing for Hurricane Katrina victims and in other mobile homes
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This article describes the health risks of exposure to formaldehyde gas in air or water, and we describe the proper steps to remove formaldehyde gas and formaldehyde gas emitting building products in order to improve indoor air quality in homes. This article includes excerpts or adaptations from Best Practices Guide to Residential Construction, by Steven Bliss, courtesy of Wiley & Sons.
Formaldehyde is a ubiquitous volatile organic compound
(VOC) that occurs in nature and is widely used in building
products, finishes, and furnishings because of its desirable
properties and low cost. Nearly all products made with
formaldehyde outgas to some extent, but only a few contribute
significantly to indoor air problems.
List of Sources of Formaldehyde Gas in buildings
Formaldehyde is used to add permanent press
qualities to clothing and drapes, as a preservative in many
paints and coatings, and as the adhesive resin in some carpeting,
fiberglass insulations, and pressed wood products. It
is also a product of combustion found in tobacco smoke and
the fumes from gas stoves and other unvented combustion.
Table 7-7 at left lists the Contributions of Formaldehyde to Room Air from various building materials and activities.
During the 1970s, it was used in urea-formaldehyde
foam insulation (UFFI), which was blown into the walls of
many homes in the U.S. and Canada and later banned after
elevated levels of formaldehyde were found in a small
number of homes. Testing has since shown that, in most
cases, any excess formaldehyde was released within a few
days of installation.
Nonetheless, the material was removed
from a large number of homes and banned for several years
in the United States and permanently banned in Canada. see Urea Formaldehyde Foam Insulation UFFI for details about UFFI insulation and formaldehyde concerns.
By far, the most significant source of formaldehyde in
homes today is pressed wood products made with urea-
formaldehyde resins. These include particle board, interior
hardwood paneling, and medium-density fiberboard
(MDF), which has the highest concentration of urea-
formaldehyde of any pressed wood product. The relative
contributions of new materials to a single room are shown
in Table 7-7, above-left.
Formaldehyde is normally present at low levels, usually
below 0.03 ppm both indoors and outdoors. However,
buildings with high levels of pressed wood products can
have higher indoor levels. For example, many manufactured
homes have levels well above 0.03 ppm, due to their
relatively small volume and large surface area of formaldehyde
emitting materials.
HUD standards that limit the
formaldehyde emissions of materials used in manufactured
housing are designed to bring the ambient level to below 0.40 ppm, still over four times the 0.10 ppm limit recommended
by most health and standards organizations,
including ASHRAE and ANSI.
No standard exists for site-
built homes.
Health Effects. Sensitivity to formaldehyde varies
widely. At levels between 0.40 and 3.0 ppm, most people
experience watery eyes, burning sensations in the nose or
throat, nausea, and difficulty breathing. Most people detect
the chemical’s pungent odor at about 0.80 ppm, but many
can smell it at concentrations as low as .05 ppm.
Formaldehyde & Asthma
High
concentrations of formaldehyde may trigger asthma attacks, and there is
strong evidence that some people can develop a sensitivity
to formaldehyde from exposure.
Formaldehyde as a Carcinogen
Formaldehyde has been conclusively linked to nasal cancer in rats, while human
studies have suggested a link to nose and throat cancer in
humans, but are not conclusive.
Based on the current
evidence the EPA and the International Agency for Research
in Cancer consider formaldehyde a probable
carcinogen prompting the lower workplace limits suggested
by the National Institute for Occupational Safety
and Health (NIOSH) (see the Formaldehyde Exposure Limits in Table 7-8 at left). More information is at Formaldehyde Exposure in Homes:A Reference for State Officials to Use in Decision-making.
Urea Formaldehyde Outgassing Sources Continue in Modern buildings
As New Zealand building investigator Paul Probett has pointed out (May 2010) that UFFI continues to be a concern as a formaldehyde outgassing source and that building moisture and formaldehyde outgassing appear to have an important relationship:
... We are becoming increasingly concerned here as [UFFI urea formaldehyde foam insulation] off gassing rates ( the company doing installs here uses USA sourced UF foam) do not seem to stabilize as quickly as some literature suggests. Since NIOSH and CDC ... [currently] class Urea Formaldehyde as a carcinogen, [see above] we have elevated concerns.
The other issue is that we are getting anecdotal evidence that when UFFI is wet it breaks down to airborne UF. In addition given your recent FEMA problem with class actions over UF release from emergency accommodation trailers used after Hurricane Katrina- the issue has a new lease of life. [See "CDC Releases Results Of Formaldehyde Level Tests" below.]
We still use UF [Urea Formaldehyde] in large quantities in particle board here ( 106kg/m3 of UF and about 20kg/m2 of Toluene) and believe we are seeing off gassing of these products from wet ... OSB ... at levels high enough to suggest high risk to long term occupants.
For a different point of view, and from a group with special interests in the formaldehyde issue, see "The Formaldehyde Fuss", published by the RV Trade association who brought in their own expert to rebut the health concerns from formaldehyde and to address public perception of formaldehyde risks in RVs and mobile homes such as in the FEMA trailers and other mobile homes - September 2007.
Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education.
Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com.
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"An Introduction to Indoor Air Quality: Formaldehyde", U.S EPA, - see http://www.epa.gov/iaq/formalde.html
Quoting:
Sources of Formaldehyde [in buildings]
Formaldehyde is an important chemical used widely by industry to manufacture building materials and numerous household products. It is also a by-product of combustion and certain other natural processes. Thus, it may be present in substantial concentrations both indoors and outdoors.
Sources of formaldehyde in the home include building materials, smoking, household products, and the use of un-vented, fuel-burning appliances, like gas stoves or kerosene space heaters. Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products. For example, it is used to add permanent-press qualities to clothing and draperies, as a component of glues and adhesives, and as a preservative in some paints and coating products.
In homes, the most significant sources of formaldehyde are likely to be pressed wood products made using adhesives that contain urea-formaldehyde (UF) resins. Pressed wood products made for indoor use include: particleboard (used as sub-flooring and shelving and in cabinetry and furniture); hardwood plywood paneling (used for decorative wall covering and used in cabinets and furniture); and medium density fiberboard (used for drawer fronts, cabinets, and furniture tops). Medium density fiberboard contains a higher resin-to-wood ratio than any other UF pressed wood product and is generally recognized as being the highest formaldehyde-emitting pressed wood product.
Other pressed wood products, such as softwood plywood and flake or oriented strand board, are produced for exterior construction use and contain the dark, or red/black-colored phenol-formaldehyde (PF) resin. Although formaldehyde is present in both types of resins, pressed woods that contain PF resin generally emit formaldehyde at considerably lower rates than those containing UF resin.
Health Effects of Formaldehyde in buildings
Formaldehyde, a colorless, pungent-smelling gas, can cause watery eyes, burning sensations in the eyes and throat, nausea, and difficulty in breathing in some humans exposed at elevated levels (above 0.1 parts per million). High concentrations may trigger attacks in people with asthma. There is evidence that some people can develop a sensitivity to formaldehyde. It has also been shown to cause cancer in animals and may cause cancer in humans. Health effects include eye, nose, and throat irritation; wheezing and coughing; fatigue; skin rash; severe allergic reactions. May cause cancer. May also cause other effects listed under "organic gases."
"An Update on Formaldehyde" (local copy), U.S. CPSC (Consumer Product Safety Commission), 1977 Revision, Original source - http://www.cpsc.gov/cpscpub/pubs/725.pd
Paul Probett, Incodo ltd Building Consultancy, Tauranga New Zealand,
Ph: 0064 7 578 7499 - Office, Post:
Incodo Ltd, Box 8202, Cherrywood, Tauranga, New Zealand, is a building expert who has addressed building moisture investigations, UFFI insulation, urea formaldehyde outgassing in buildings. Mr. Probett reports (2 May 2010):
We have a major leaky home problem here with probably 80-100,000 homes built in the last 25 years which leak badly and require on average about $180K US to remediate. Causes are an interesting subject by themselves, but government here acknowledges they had something to do with it and employ people like me to investigate and report for a token fee to the public.
Needless to say our investigation techniques have developed sharply and standard inspection for moisture intrusion includes NDT [non-destructive moisture and leak investigation techniques] using thermal imagers in concert with both microwave and dielectric constant moisture meters (Favoured brand is the German Trotec™ T2000 multiunit . We have also sharpened our way of measuring moisture in non timber materials using Trotec or Gann resistance probes to take readings from a variety of materials as well as using narrow diameter temp/humidity probes. I add to the mix using Logtag data loggers cards to identify dew point problems.
... We are becoming increasingly concerned here as off gassing rates ( the company doing installs here uses USA sourced UF foam) do not seem to stabilize as quickly as some literature suggests. Since NIOSH and CDC now ( recently anyway) class UF as a carcinogen we have elevated concerns.
The other issue is that we are getting anecdotal evidence that when UFFI is wet it breaks down to airborne UF. In addition given your recent FEMA problem with class actions over UF release from emergency accommodation trailers used after Hurricane Katrina- the issue has a new lease of life.
We still use UF in large quantities in particle board here ( 106kg/m3 of UF and about 20kg/m2 of Toluene) and believe we are seeing off gassing of these products from wet what you call OSB I think. - at levels high enough to suggest high risk to long term occupants. ... I like Gastec sorbent tubes over Draeger - simpler quicker and cheaper.
Looking forward to getting a Walleye Technologies microwave imager for inspection purposes as soon as they're released - looks a very promising tool for the box
Trotec, or in English: Trotec a German producer of measuring equipment for construction diagnostics, with offices also in Austria and France, Tel. +49 (0) 2452 / 962-450, E-Mail: online@trotec.de
"CDC Releases Results Of Formaldehyde Level Tests", 14 February 2008, original source:
- http://www.fema.gov/news/newsrelease.fema?id=42606
Quoting from portions of that document:
NEW ORLEANS, La. -- The Centers for Disease Control and Prevention (CDC) and the Federal Emergency Management Agency (FEMA) released today preliminary results from recent testing that found higher than typical indoor exposure levels of formaldehyde in travel trailers and mobile homes used as emergency housing in the Gulf Coast Region.
... These findings support FEMA's continued focus on finding permanent housing for everyone who has been living in travel trailers and mobile homes since the hurricanes," said CDC Director Dr. Julie Gerberding. "The levels in many of these trailers and mobile homes are higher than would be expected indoors. Since these levels were found in December and January, and we know that higher temperatures can cause formaldehyde levels to go up, we think it's wise for people to be relocated before the hot weather arrives in summer. We also think that it would be beneficial for people who are displaying symptoms as well as households with children, elderly persons, or occupants with chronic respiratory illnesses to receive priority consideration for alternate housing.
CDC's preliminary evaluation of a scientifically established random sample of 519 travel trailers and mobile homes tested between Dec. 21, 2007 and Jan. 23, 2008 showed average levels of formaldehyde in all units of about 77 parts per billion (ppb). Long-term exposure to levels in this range can be linked to an increased risk of cancer, and as levels rise above this range, there can also be a risk of respiratory illness. These levels are is higher than expected in indoor air, where levels are commonly in the range of 10-20 ppb. Levels measured ranged from 3 ppb to 590 ppb.
CDC and FEMA recommend that Gulf Coast families living in travel trailers and mobile homes spend as much time outdoors in fresh air as possible. Residents should open windows to let fresh air in whenever possible, and try to maintain the temperature inside their travel trailers or mobile homes at the lowest comfortable level. Higher temperatures can cause greater release of formaldehyde. Persons who have health concerns are encouraged to see a doctor or another medical professional.
The two agencies have established toll-free hotlines. FEMA employees are available to discuss housing concerns at 1 (800) 621-FEMA (3362), or TDD: 1 (800) 462-7585. CDC specialists will respond to health-related concerns at 1-800- CDC-INFO.
"Formaldehyde and Travel Trailers", U.S. Department of Homeland Security - FEMA, 20 July, 2007, original source: - http://www.fema.gov/news/newsrelease.fema?id=36730 Quoting from portions of that document:
Of the 120,000 travel trailers and mobile homes provided to survivors of hurricanes Katrina and Rita in the Gulf, FEMA has documented 206 complaints of strange odors, including formaldehyde complaints. At residents' requests, FEMA switched out units for trailers that had already been used and ventilated. FEMA distributed information to trailer occupants across the country explaining how persons sensitive to formaldehyde may be affected by its presence and laid out actions that should be taken to reduce exposure in the trailers.
All new, unused and unventilated travel trailers have formaldehyde in them. The concentration of formaldehyde can be reduced significantly by ventilating the units by running fans with open doors and windows. Other factors that affect the levels of formaldehyde indoors include the type and age of source materials, temperature and humidity. It also is important to recognize that some people are more sensitive to the effects of formaldehyde than others.
Based on issues recently brought to our attention and new questions about health effects of formaldehyde, FEMA has again engaged the scientific community to review current concerns about the effects of formaldehyde on travel trailer residents of the Gulf. In conducting this re-evaluation, FEMA has teamed up with the Department of Homeland Security Office of Health Affairs (DHS OHA), and multiple agencies within the Centers for Disease Control and Prevention (CDC). Of note, these evaluations will not be limited to formaldehyde, but will take a holistic view of analyzing symptoms and possible causes. These agencies will work together to determine the relationship between the air quality in FEMA's travel trailers and the health of the residents who live in them.
The HUD standard places limits on formaldehyde emissions and product certification of all plywood and particleboard materials, which involves emission certification by a nationally recognized testing laboratory and a written quality control plan for each plant where particle board is produced or finished or where the plywood is finished. These standards have been required by HUD for manufactured homes, and now FEMA's specifications have incorporated those same standards for travel trailers.
The HUD standards also require that each manufactured home be provided with a Health Notice on formaldehyde emissions as required by 3280.309 of the Standards. Adjustments to this will be made based on the findings of follow-up reviews by agencies responsible for determining the effects of formaldehyde and potentially setting standards.
"The Formaldehyde Fuss", 25 Sept. 2007, RV Trade Digest, web search 05/03/2010 - see http://www.rvtradedigest.com/interactive/2007/09/25/the-formaldehyde-fuss/
Quoting from the RV trade association's article:
The association brought in a hired gun to bring manufacturers, dealers and suppliers up to speed about the issue which has garnered media attention to the point some consumers wonder whether they’ll be poisoned in their RVs, as some media outlets have contended. The bottom line is that the media hype is groundless and it is up to us to educate consumers about the formaldehyde fuss. ...
Dr. Lee Shull is a professional toxicologist who works as the corporate risk services director for Environmental Resources Management in Sacramento, Calif. He was invited by RVIA [The Recreation Vehicle Industry Association (RVIA) is the national trade association representing recreation vehicle (RV) manufacturers and their components - www.rvia.org] to expose the fallacy of the formaldehyde issue. ... he did an excellent job putting the issue in its proper context. Here are a few bullet points you can use to reassure customers that RVs remain safe.
Formaldehyde is one of the most naturally occurring organic compounds in the universe
It is not unusual for people to be exposed to formaldehyde daily through clothing, carpeting, building materials and even food
It is often used as a disinfectant and antimicrobial solution
It is fed to livestock
It is found in soap and cosmetics
It is used in the food industry to process fish, cheese and juice
It has been used for 70 years to create exceptionally strong glue that securely bonds one material to another
[Watch out: the comments on Formaldehyde by RVIA and Dr. Shull, and summarized above, do not address the formaldehyde health research nor formaldehyde outgassing advice provided by the U.S. CDC, Department of Homeland Security, FEMA, and the US EPA, and other experts.]
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