Formaldehyde

This pamphlet provides answers to basic questions about formaldehyde. It will explain what formaldehyde is, where it can be found, how it can affect your health, and what you can do to prevent or reduce exposure to it.

A family recently installed a new counter top and cabinets in their kitchen. After the installation was completed, an odor seemed to linger. That evening, while cleaning up after dinner, the mother’s eyes began to water and the youngest son started coughing. When they left the kitchen, they noticed that the symptoms went away.

Formaldehyde is a colorless gas with a strong, suffocating odor. It often is mixed with alcohol to make a liquid called formalin. The largest source of formaldehyde is the chemical manufacturing industry. Formaldehyde is found in cigarette smoke and also can be formed in the environment during the burning of fuels or household waste. Very small amounts of formaldehyde are found naturally in the human body.

Formaldehyde can be used for many purposes and is a popular chemical because of its low cost. It can be found in items such as plywood, particle board, and other pressed wood products that are commonly used to make furniture, cabinets, wall paneling, shelves, and counter tops. Formaldehyde also can be used to kill germs or as a preservative, and is found in some commercial products. It also is found in items such as dyes, textiles, plastics, paper products, fertilizer, and cosmetics.

Formaldehyde was a component in urea formaldehyde foam insulation (UFFI). This type of insulation was installed in many homes during the 1970s and early 1980s. Due to potential health concerns associated with UFFI, the demand for this product became virtually nonexistent and it has rarely been used since 1983. Although older homes may still contain UFFI, any formaldehyde releases would have occurred in the first five years following installation and would no longer be a cause for concern.

The most common way to be exposed to formaldehyde is by breathing air containing formaldehyde. This usually occurs in indoor environments where the gas has been released from formaldehyde-containing products. Exposure to liquid formalin may be through the skin or by ingestion.

Breathing air containing low levels of formaldehyde can cause burning and watering eyes. As levels increase, it can cause burning of the nose and throat, coughing, and difficulty in breathing. Some people may be more sensitive to formaldehyde and have effects at levels lower than expected.

Strong mixtures of formaldehyde gas or liquid can cause irritation or a rash if they contact the skin. When swallowed, formaldehyde can cause severe pain, vomiting, and diarrhea. Formaldehyde that enters the blood stream can produce effects similar to drinking too much alcohol.

Animal studies have shown increased nasal cancers in rats and mice who inhaled high levels of formaldehyde for a long time. Because of this, the United States Environmental Protection Agency has classified formaldehyde as a probable human carcinogen (cancer causing agent). This means there is enough evidence that formaldehyde causes cancer in animals, but not enough evidence that it causes cancer in humans. Human studies are inconclusive because it is not known whether observed increases in cancer are due to formaldehyde exposure or to other factors, such as smoking.

Products that contain formaldehyde compounds can release formaldehyde gas into the air. These types of releases are known as "off gassing" and they occur most often in products such as plywood, particle board, and other pressed wood products. The amount released is greatest when the product is new, and decreases over time. Formaldehyde is released more readily at warm temperatures and high humidity.

In manufactured homes that contain large amounts of pressed wood products, there are concerns about the initial indoor level of formaldehyde. In 1984, the U.S. Department of Housing and Urban Development (HUD) set standards for construction of manufactured homes. These standards require that manufacturers only use pressed wood products that release formaldehyde at levels below an accepted guideline. The standards also require that a health notice concerning formaldehyde emissions be included on all new manufactured homes.

Because of its strong odor, formaldehyde can be smelled at very low levels. The typical person can smell formaldehyde at levels less than those that might cause health effects. People who are hypersensitive or who have respiratory problems may experience effects at levels lower than what can be smelled. There are ways of testing the air to learn how much formaldehyde is present. If you think that your home may have high levels of formaldehyde, contact your local health department for more information.

A simple and effective way to reduce formaldehyde levels in the home is to increase air flow in the affected area by opening windows and doors. This lowers the level of formaldehyde by increasing the amount of outdoor air. Usually, the levels decrease and odors are gone within a few days.

Another way to reduce exposure is to apply a barrier between formaldehyde containing surfaces and the indoor air. Products such as latex-based paints or varnish can block formaldehyde “off gasses.” The use of vinyl coverings such as wallpaper and floor covering on particle board panels also has been effective. If all other efforts fail to reduce formaldehyde to manageable levels, removing formaldehyde containing products from the home environment may be necessary.

Illinois Department of Public Health 
Division of Environmental Health 
525 W. Jefferson St. 
Springfield, IL 62761 
217-782-5830 
TTY (hearing impaired use only) 800-547-0466

This pamphlet was supported in part by funds from the Comprehensive Environmental Response, Compensation, and Liability Act trust fund through a cooperative agreement with the Agency for Toxic Substances and Disease Registry, Public Health Service, U.S. Department of Health and Human Services.