Formaldehyde
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.
For
further information on formaldehyde and consumer products, call the EPA Toxic Substance Control Act (TSCA)
Assistance
Line (202) 554-1404.
Contents
Background
Since 1985, the Department of Housing and Urban Development (HUD) has permitted only
the use of plywood and particleboard that conform to specified formaldehyde emission limits in the construction of prefabricated
and mobile homes. In the past, some of these homes had elevated levels of formaldehyde because of the large amount of high-emitting
pressed wood products used in their construction and because of their relatively small interior space.
The rate at which
products like pressed wood or textiles release formaldehyde can change. Formaldehyde emissions will generally decrease as
products age. When the products are new, high indoor temperatures or humidity can cause increased release of formaldehyde
from these products.
During the 1970s, many homeowners had urea-formaldehyde foam insulation (UFFI) installed in the
wall cavities of their homes as an energy conservation measure. However, many of these homes were found to have relatively
high indoor concentrations of formaldehyde soon after the UFFI installation. Few homes are now being insulated with this product.
Studies show that formaldehyde emissions from UFFI decline with time; therefore, homes in which UFFI was installed many years
ago are unlikely to have high levels of formaldehyde now.
Sources of Formaldehyde
Pressed wood products (hardwood plywood wall paneling, particleboard, fiberboard)
and furniture made with these pressed wood products. Urea-formaldehyde foam insulation (UFFI). Combustion sources and environmental
tobacco smoke. Durable press drapes, other textiles, and glues.
Health Effects
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." EPA's Integrated Risk Information
System profile - www.epa.gov/iris/subst/0419.htm
Levels in Homes
Average concentrations in older homes without UFFI are generally well below 0.1
(ppm). In homes with significant amounts of new pressed wood products, levels can be greater than 0.3 ppm.
Steps to Reduce Exposure
- Use "exterior-grade" pressed wood products (lower-emitting because
they contain phenol resins, not urea resins).
- Use air conditioning and dehumidifiers to maintain moderate temperature
and reduce humidity levels.
- Increase ventilation, particularly after bringing new sources of formaldehyde into the
home.
Ask about the formaldehyde content of pressed wood products, including building materials, cabinetry, and
furniture before you purchase them.
If you experience adverse reactions to formaldehyde, you may want to
avoid the use of pressed wood products and other formaldehyde-emitting goods. Even if you do not experience such reactions,
you may wish to reduce your exposure as much as possible by purchasing exterior-grade products, which emit less formaldehyde.
For further information on formaldehyde and consumer products, call the EPA Toxic Substance Control Act (TSCA) assistance
line (202-554-1404).
Some studies suggest that coating pressed wood products with polyurethane may reduce formaldehyde
emissions for some period of time. To be effective, any such coating must cover all surfaces and edges and remain intact.
Increase the ventilation and carefully follow the manufacturer instructions while applying these coatings. (If you are sensitive
to formaldehyde, check the label contents before purchasing coating products to avoid buying products that contain formaldehyde,
as they will emit the chemical for a short time after application.)
Maintain moderate temperature and humidity
levels and provide adequate ventilation.
The rate at which formaldehyde is released is accelerated by heat
and may also depend somewhat on the humidity level. Therefore, the use of dehumidifiers and air conditioning to control humidity
and to maintain a moderate temperature can help reduce formaldehyde emissions. (Drain and clean dehumidifier collection trays
frequently so that they do not become a breeding ground for microorganisms.) Increasing the rate of ventilation in your home
will also help in reducing formaldehyde levels.
Additional Resources
An Update on Formaldehyde: 1997 Revision (CPSC document #725)
The
U.S. Consumer Safety Commission has produced this booklet to tell you about formaldehyde found in the indoor
air. This booklet tells you where you may come in contact with formaldehyde, how it may affect your health, and how you might
reduce your exposure to formaldehyde.
U.S. Dept. of Health and Human Services, Agency for Toxic Substances and Disease Registry
(ATSDR) - ToxFAQs for Formaldehyde, July 1999
Occupational Safety and Health Administration's fact sheet on Formaldehyde - www.osha.gov/SLTC/formaldehyde/
The National Safety Council's Environmental Health Center fact sheet on Formaldehyde 
American Lung Association
1740 Broadway
New York, NY 10019-4374
(local ALA offices also have information)
