Market Intelligence

Green & Sustainable Construction

Formaldehyde Use in Building Construction

Formaldehyde is a chemical used widely to manufacture building materials and products, such as glue in fiberboard. Formaldehyde is also a by-product of combustion and certain other natural processes. Thus, it may be present in substantial concentrations both indoors and out.

Sources of formaldehyde include building materials; smoking; household products; and the use of un-vented, fuel-burning appliances, such as fork lifts, gas stoves, or kerosene space heaters.

Formaldehyde, by itself or in combination with other chemicals, is used for 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 smaller facilities and 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 subflooring and shelving and in cabinetry and furniture)
  • hardwood plywood paneling (used for decorative wall covering and in cabinets and furniture)
  • 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 emitting the highest levels of formaldehyde.

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.

Since 1985, the Department of Housing and Urban Development (HUD) has permitted the use of plywood and particleboard only if they conform to specified formaldehyde emission limits in the construction of prefabricated panels. In the past, some construction using prefabricated panels had elevated levels of formaldehyde because of the large amount of high-emitting pressed wood products used in their construction.

The rate at which products such as pressed wood or textiles release formaldehyde can change. Formaldehyde emissions generally decrease as products age. When products are new, high indoor temperatures or humidity can cause increased release of formaldehyde.

During the 1970s, many properties had urea-formaldehyde foam insulation (UFFI) installed in the wall cavities as an energy conservation measure. However, many of these properties were found to have relatively high indoor concentrations of formaldehyde soon after the UFFI installation. Use of this product has been declining. Studies show that formaldehyde emissions from UFFI decrease with time; therefore, homes in which UFFI was installed many years ago are unlikely to have high levels of formaldehyde now.

Formaldehyde, a colorless, pungent-smelling gas, can cause eye, nose, and throat irritation; wheezing and coughing; fatigue; skin rash; and severe allergic reactions. High concentrations may trigger attacks in people with asthma. There is evidence that some people can develop a sensitivity to formaldehyde, which has also been shown to cause cancer in animals and may cause cancer in humans.

The average concentration of formaldehyde in older properties without UFFI is generally below 0.1 PPM (parts per million). In properties with significant amounts of new pressed wood products, levels can be greater than 0.3 PPM. Coatings may reduce formaldehyde emissions for some period of time. To be effective, the coating must cover all surfaces and edges and remain intact.

Since release of formaldehyde may be affected by the humidity level (as well as heat), dehumidifiers and air conditioning can help reduce emissions. (Drain and clean dehumidifier collection trays frequently so that they do not become a breeding ground for microorganisms.) Increasing the rate of ventilation will also help reduce formaldehyde levels.

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