This content has been adapted from the National Cancer Institute Fact Sheet, Formaldehyde and Cancer Risk, available online at: www.cancer.gov/cancertopics/factsheet/Risk/formaldehyde
What is formaldehyde?
Formaldehyde is a colorless, strong-smelling chemical that is used to make building materials and many household products. It is used in pressed-wood products, such as particleboard, plywood, and fiberboard; glues and adhesives; permanent-press fabrics; paper product coatings; and certain insulation materials. It is also commonly used as an industrial disinfectant, and as a preservative in funeral homes and medical labs.
Formaldehyde also occurs naturally in the environment. Most living organisms make small amounts as part of normal metabolic processes.
How are people exposed to formaldehyde?
According to the US Consumer Product Safety Commission, formaldehyde is normally present at low levels in both indoor and outdoor air. Materials containing formaldehyde can release it as a gas or vapor into the air. One example of formaldehyde exposure in the air is through automobile exhaust.
During the 1970s, urea-formaldehyde foam insulation (UFFI) was used in many homes. But few homes are now insulated with UFFI. Homes in which UFFI was installed many years ago are not likely to have high formaldehyde levels now.
Pressed-wood products containing formaldehyde resins are often a source of formaldehyde in homes. Other potential indoor sources of formaldehyde include cigarette smoke and the use of unvented fuel-burning appliances, such as gas stoves, wood-burning stoves, and kerosene heaters.
Workers in industries that make formaldehyde or formaldehyde-containing products, lab technicians, some health care professionals, and funeral home employees may be exposed to higher levels of formaldehyde than the general public. Exposure occurs mainly by inhaling formaldehyde gas or vapor from the air or by absorbing liquids containing formaldehyde through the skin.
Formaldehyde is also a component of tobacco smoke. A recent study found much higher levels of formaldehyde bound to DNA in the white blood cells of smokers compared to non-smokers.
What are the short-term health effects of formaldehyde exposure?
When formaldehyde is present in the air at levels higher than 0.1 parts per million (ppm), some people may have health effects, such as:
- watery eyes
- burning sensations of the eyes, nose, and throat
- skin irritation
Some people are very sensitive to formaldehyde, but others have no reaction to the same level of exposure.
Can formaldehyde cause cancer?
The short-term health effects of formaldehyde exposure are well known, but less is known about its possible long-term effects.
What studies have found
In 1980, lab studies showed that exposure to formaldehyde could cause nasal cancer in rats. This finding raised the question of whether it could also cause cancer in humans. Since then, the US National Cancer Institute (NCI) and other groups have done studies to find out whether there is a link between workplace exposure to formaldehyde and an increased risk of cancer.
Formaldehyde goes through rapid chemical changes right after entering the body. Therefore, some scientists think that formaldehyde is most likely to have effects on the upper respiratory tract. Several studies have reported a link between formaldehyde exposure and cancer of the nasopharynx (the uppermost part of the throat), but some other studies have not. Some earlier studies suggested that formaldehyde exposure might be linked to lung cancer, but more recent results have not found such a link.
Several NCI studies have found that anatomists and embalmers – people who are potentially exposed to formaldehyde in their professions – are at an increased risk of leukemia, and some studies have suggested an increased risk of brain cancer as well. An NCI study looking at more than 25,000 workers potentially exposed to formaldehyde found an increased risk of death due to lymphoma and leukemia, particularly myeloid leukemia.
A separate study of textile workers done by the US National Institute for Occupational Safety and Health (NIOSH) also found a link between the length of exposure to formaldehyde and leukemia deaths. But a large study of British industry workers found no link between cumulative formaldehyde exposure and leukemia deaths.
A recent study found that workers exposed to formaldehyde had higher than normal levels of chromosome changes in early white blood cells in their bone marrow. This finding supports the possible link between formaldehyde exposure and leukemia.
What expert agencies say
Several agencies (national and international) study different substances in the environment to determine if they can cause cancer. (A substance that causes cancer or helps cancer grow is called a carcinogen.) The American Cancer Society looks to these organizations to evaluate the risks based on evidence from laboratory, animal, and human research studies.
Based on the available evidence, some of these expert agencies have evaluated the cancer-causing potential of formaldehyde.
The National Toxicology Program (NTP) is formed from parts of several different US government agencies, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA). Exposures that are thought to be carcinogenic are included in the Report on Carcinogens, published every few years. The NTP lists formaldehyde as "known to be a human carcinogen."
The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO). Its major goal is to identify causes of cancer. IARC has concluded that formaldehyde is "carcinogenic to humans" based on higher risks of nasopharyngeal cancer and leukemia.
The Environmental Protection Agency (EPA) maintains the Integrated Risk Information System (IRIS), an electronic database that contains information on human health effects from exposure to various substances in the environment. The EPA has classified formaldehyde as a "probable human carcinogen."
National Cancer Institute researchers have concluded that, based on data from studies in people and from lab research, exposure to formaldehyde may cause leukemia, particularly myeloid leukemia, in humans.
(For more information on the classification systems used by some of these agencies, see our document, Known and Probable Human Carcinogens.)
What has been done to protect workers from formaldehyde?
In 1987, the US Occupational Safety and Health Administration (OSHA) established a federal standard that reduced the amount of formaldehyde to which workers can be exposed over an 8-hour work day from 3 ppm to 1 ppm. In 1992, the formaldehyde exposure limit was further reduced to 0.75 ppm.
How can people limit formaldehyde exposure in their homes?
The EPA recommends using "exterior-grade" pressed-wood products to limit formaldehyde exposure in the home. These products give off less formaldehyde because they contain phenol resins, not urea resins. Before buying pressed-wood products, including building materials, cabinetry, and furniture, buyers should ask about the formaldehyde content of these products.
Formaldehyde levels in homes can also be reduced by not allowing smoking inside and by ensuring adequate ventilation, moderate temperatures, and reduced humidity levels through the use of air conditioners and dehumidifiers.
More information from your American Cancer Society
The following related information may also be helpful to you. These materials may be viewed on our web site or ordered from our toll-free number, at 1-800-227-2345.
National organizations and web sites
In addition to the American Cancer Society, other sources of information and support include*:
US Consumer Product Safety Commission
Toll-free number: 1-800-638-2772 (1-800-638-CPSC)
Web site: www.cpsc.gov
The Consumer Product Safety Commission (CPSC) has information about household products that contain formaldehyde.
US Food and Drug Administration
Toll-free number: 1-888-463-6332 (1-888-INFO-FDA)
Web site: www.fda.gov
The Food and Drug Administration (FDA) maintains information about cosmetics and drugs that contain formaldehyde.
Occupational Safety and Health Administration
Toll-free number: 1-800-321-6742 (1-800-321-OSHA)
Web site: www.osha.gov
The Occupational Safety and Health Administration (OSHA) has information about workplace exposure limits for formaldehyde.
Federal Emergency Management Agency
Toll-free number: 1-800-621-3362 (1-800-621-FEMA)
Web site: www.fema.gov
The Federal Emergency Management Agency (FEMA) has information about formaldehyde exposure levels in mobile homes and trailers supplied by FEMA after Hurricane Katrina.
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Last Revised: 06/13/2011