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Note: This Instructional Module information comes from our Training Manual. The complete Training Manual can be ordered from our Program and comes with a video, transparency masters, module publications, and many other educational resources.Module Learning Objectives
Support Publications
Notes to the Program Leader:Because of its useful properties, formaldehyde is found in a wide variety of furnishings, building materials, etc. Formaldehyde is also a powerful irritant (eyes, nose, throat) and is among the most common causes of occupant discomfort and complaints. This module discusses major formaldehyde sources and provides information for reducing formaldehyde levels. Leaders may wish to refer to the "Household Products" module for related information.Audiences for this program include housing occupants, especially
those in newer homes; mobile home occupants; and people in households with
veneered or "knock down" furnishings. This presentation should take 20-30
minutes.
Script for Transparency #1 WHAT IS FORMALDEHYDE? Formaldehyde is a chemical that is released into the air as a pungent vapor; many of us remember this smell from the high school biology lab. Formaldehyde is a strong irritant that affects the eyes, nose, throat and skin and may also cause headaches and fatigue. Formaldehyde has a number of useful properties. It is a good preservative
and makes an excellent adhesive, so it has found many uses in the building
and furnishings industries. It is also found in small amounts in some textiles
as an anti-wrinkle (permanent-press) agent.
Script for Transparency #2 HEALTH EFFECTS OF FORMALDEHYDE EXPOSURE Low doses cause watery eyes or burning sensations in the eyes, nose, and throat. Larger doses can cause nausea, breathing difficulties, headaches, and fatigue. High doses can cause asthma attacks. Some people are highly sensitive to formaldehyde and react to concentrations that would not bother other people. Formaldehyde has been shown to cause cancer in laboratory animals, but
to date there is limited evidence it has caused increased incidence of
cancer in humans. Nevertheless, it is classified as a "probable human carcinogen"
by the EPA and the National Institute for Occupational Safety and Health
(NIOSH).
Script for Transparency #3 SOURCES OF FORMALDEHYDE In most homes, particle board and medium density fiberboard (MDF) are by far the major sources of formaldehyde in the environment. Some particle board is now manufactured with reduced formaldehyde, thus helping the problem to some degree. The culprit is the adhesive urea formaldehyde which can break down and release formaldehyde. A related adhesive, called phenol formaldehyde (used in softwood plywood and oriented-strand board) releases little, if any, formaldehyde. Therefore, products with phenol formaldehyde are widely recommended as substitutes for problematic board products. Oriented-strand board is now widely used for flooring and roof decking. In the mid-1980s, some homes had severe problems due to improperly mixed urea formaldehyde foam insulation (UFFI). This product was taken off the market and is virtually unavailable today. Foams installed back then are unlikely to cause problems today. Other types of foam insulation are not associated with such problems. Some commercially-applied furniture and floor finishes (acid-cured finishes) can also release formaldehyde. Hardwood plywood, paneling, and interior plywood are sources of formaldehyde as well. Permanent-press fabrics, some other textiles, and cosmetics are sources of trace amounts of formaldehyde. In addition, formaldehyde is produced by combustion processes, including gas flame and cigarette smoke. Formaldehyde emissions can continue for a long time after original product
manufacture; emissions and concentration levels are increased by elevated
temperature and humidity.
Script for Transparency #4 DETECTION OF FORMALDEHYDE Those who are familiar with the characteristic smell of formaldehyde may be able to identify it by its odor. (The formaldehyde symptoms we have mentioned are not much help in identifying this substance since these symptoms are also produced by a wide array of other irritants.) Environmental testing firms (listed in the yellow pages of the phone directory) should be able to provide testing for residential formaldehyde levels. Since such tests are costly, it is wise to establish some reasonable suspicion that formaldehyde is present before considering testing. The presence of abundant formaldehyde-containing materials would be one indication of a problem, especially if these materials have been in place in the home for less than one year. Do-it-yourself test kits are available by mail. However, there are some concerns about the accuracy of test results, especially at the lower levels that might be seen in homes. Moreover, there does not presently exist any certification program or other standard to assure the reliability of these tests. Standards: The U.S. does not have any standards for formaldehyde
in residential indoor air. A ventilation organization has proposed a voluntary
standard of 0.10 parts per million (although this level can still cause
problems for sensitive individuals). Some agencies recommend lower levels.
Script for Transparency #5 REDUCING FORMALDEHYDE PROBLEMS Existing homes. The first step in reducing formaldehyde problems in existing homes is to identify possible sources. As mentioned earlier, likely sources include particle board, MDF, acid-cured finishes, paneling and hardwood plywood, and cabinets and furnishings made from these materials. Such furnishings are often covered with plastic laminate, veneer, or a "woodgrain" covering. Formaldehyde cannot penetrate plastic laminate and is at least partly blocked by coatings. Although special formaldehyde sealants are available, varnishes (polyurethane and nitrocellulose) are also effective in this regard (two coats are preferred). Coatings should be applied to all exposed edges and surfaces (for example, the underside of countertops, and cabinet interiors and drawers). Since high humidity and elevated temperatures increase formaldehyde release, these conditions should be controlled when possible. Air conditioning, dehumidifiers, and other moisture control measures should be explored, as appropriate. Additionally, ventilation can help lower indoor formaldehyde levels when outdoor weather conditions permit. New construction. In new construction, specify the use of low-emitting
or formaldehyde-free materials. Veneered furniture can be replaced by solid
wood furniture or old furniture, and particle board can by replaced by
exterior softwood plywood or a similar product -- wafer board (not associated
with formaldehyde problems). Some particle board is now manufactured to
have "lower" formaldehyde emissions. (These products are identified by
a stamp indicating compliance with HUD standards for formaldehyde emissions.)
While this is an improvement, there is still no guarantee that indoor formaldehyde
levels will be acceptable.
Note to the Program Leader: Although there have been press
reports about research showing certain plants (i.e., spider plants) can
absorb formaldehyde and other indoor pollutants, other studies show such
effects are limited and it would be impractical (or impossible) to have
enough plants to counteract continuous formaldehyde emissions (Resource:
"An Update on Formaldehyde," CPSC).
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