FORMALDEHYDE

FORMALDEHYDE

Formaldehyde is an important chemical used widely by industry to
manufacture building materials and numerous household products.
It is also a byproduct 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 unvented,
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
ureaformaldehyde (UF) resins. Pressed wood products made for
indoor use include: particle board (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 phenolformaldehyde
(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.

Since 1985, the Department of Housing and Urban Development (HUD)
has permitted only the use of plywood and particle board 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 ureaformaldehyde 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

(continued on page 23)

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.

Health Effects of Formaldehyde

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.

Reducing Exposure to Formaldehyde in Homes

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
(2025541404).

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 s 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.