What is formaldehyde?
Formaldehyde is a colorless and flammable gas with a distinct odor detectable at very low concentrations. It is a volatile organic compound (VOC) that causes cancer and other harmful health effects.1 Formaldehyde is a naturally occurring chemical; our bodies even produce small amounts of formaldehyde. However, at high concentrations, formaldehyde vapors are dangerous.
What are the health effects of formaldehyde in indoor air?
Formaldehyde causes cancer.1,2 Evidence shows formaldehyde can cause a rare cancer of the nasopharynx, which is the upper part of the throat behind the nose.
Formaldehyde irritates the nose, eyes, and throat. These irritations can happen at low levels of formaldehyde, especially in people who are especially sensitive to the odors.1,2 Other short-term effects include headache, runny nose, nausea and difficulty breathing.3 Exposure may cause wheezing, asthma attacks and other respiratory symptoms.4
Individuals vary in how they respond to formaldehyde. Some people have a natural allergic sensitivity to airborne formaldehyde and others may develop an allergy as a result of skin contact with liquid formaldehyde.3 Researchers have found that some individuals with asthma are more vulnerable to the effects of inhaled formaldehyde.1
What are the sources of formaldehyde indoors?
Many industries use formaldehyde. It is used to produce wood, paper, plywood, glues and adhesives, permanent press fabrics, some paints and coatings, and certain insulation materials. It is also found in many consumer products, including cosmetics, dish soaps, medicines, leather treatments and fabric softeners.4
Formaldehyde is present both indoors and outdoors. However, formaldehyde levels are usually much higher indoors. Because formaldehyde is volatile, which means it evaporates easily, it is released into the air from many products inside the home. High humidity and high temperatures speed up the release of formaldehyde.
Smoking indoors produces high concentrations of formaldehyde. Burning wood products, fuel, paper and other products is also an important source of formaldehyde.
How can you reduce exposure to formaldehyde indoors?
There are a few simple ways to protect yourself from formaldehyde indoors.
- Chose low-formaldehyde products when building or remodeling. Furniture and pressed-wood board made with laminated surfaces release less formaldehyde and other VOCs. If possible, use non-toxic alternatives to formaldehyde-containing products like glue and adhesives.
- Ventilate indoor spaces. Open windows or use exhaust fans to blow indoor air out and bring fresh air in. Make sure any combustion appliance has a separate exhaust to the outdoors. Remember to ventilate indoor spaces when using cleaners, cosmetic products like nail polish remover or most paints.
- Air out new furniture and pressed-wood products. Many consumer products that emit formaldehyde, such as plywood and particle board, release the highest concentrations when they are new. Air them out before installing them or bringing them indoors.
- Don't allow smoking indoors. Not smoking and prohibiting smoking indoors can reduce exposure to formaldehyde. Secondhand smoke contains many chemicals in addition to formaldehyde that can harm health.
- Wash permanent press clothing before wearing. Formaldehyde is used in the production of special fabrics.
- Agency for Toxic Substances and Disease Registry (ATSDR). Tox FAQs for Formaldehyde. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. 2011. Accessed August 26, 2015.
- California Air Resources Board (CARB). Report to the California Legislature: Indoor Air Pollution in California. Sacramento, CA: California Environmental Protection Agency. 2005.
- Agency for Toxic Substances and Disease Registry (ATSDR). Revised Health Consultation –Formaldehyde Sampling at FEMA Temporary Housing Units - Baton Rouge, Louisiana. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. 2007.
- Institute of Medicine, Division of Health Promotion, Indoor Air and Disease Prevention. Clearing the Air: Asthma and Indoor Air Exposures. Washington, DC: National Academies Press. 2000; Kanchongkittiphon W, et al. Indoor Environmental Exposures of Asthma: An Update to the 2000 Review by the Institute of Medicine. Environmental Health Perspectives. 2015; 123: 6-20.
Approved by Scientific and Medical Editorial Review Panel. Last reviewed December 7, 2017.