Formaldehyde

What is formaldehyde?

In the manufacturing of building materials and many household products, formaldehyde is a strong-smelling, colorless gas. A variety of pressed-wood products, including particleboard, plywood and fiberboard, adhesives, permanent-press fabrics, paper product coatings, and certain insulation materials use the material. Other chemicals are also made from it.

Formaldehyde is rapidly decomposed in the air - generally within hours. Water readily dissolves it, but it does not last long in it.

Formalin is a chemical compound that dissolves in water, and is commonly used as an industrial disinfectant as well as a preservative in funeral homes and medical laboratories. It is also used as a preservative in some foods and products, such as antiseptics, medicines, and cosmetics. Occasionally, formaldehyde is not used but substances that release formaldehyde are. Chemicals such as these can be found in cosmetics, soaps, shampoos, lotions, sunscreens, and cleaning products.

Formaldehyde can be added to food as a preservative, but it can also be formed during cooking and smoking.

There is also naturally occurring formaldehyde. As part of their normal metabolic processes, humans and most other living organisms produce very small amounts.

How are people exposed to formaldehyde?

The main way people are exposed to formaldehyde is by inhaling it. The liquid form can be absorbed through the skin. People can also be exposed to small amounts by eating foods or drinking liquids containing formaldehyde.

Our bodies produce formaldehyde naturally. It can then be broken down further into carbon dioxide by enzymes in the body. Less than a third of inhaled formaldehyde is absorbed into the bloodstream by the cells lining the mouth, nose, throat, and airways.

In both indoor and outdoor air, formaldehyde is normally present at low levels (less than 0.03 parts per million), according to the Consumer Product Safety Commission. As a gas or vapor, formaldehyde can be released into the air by materials containing it. Formaldehyde is a major component of outdoor air due to automobile exhaust.

In the 1970s, many homes used urea-formaldehyde foam insulation (UFFI). Today, few homes use UFFI. Formaldehyde levels are unlikely to be high in homes which had UFFI installed many years ago.

Homes often contain formaldehyde from pressed-wood products containing formaldehyde resin. It is also possible to raise formaldehyde levels indoors by using fuel-burning appliances without ventilation, such as gas stoves, wood-burning stoves, and kerosene heaters.

Smokers and secondhand smokers are exposed to higher levels of formaldehyde because formaldehyde is a component of tobacco smoke. White blood cells of smokers contained higher levels of DNA-bound formaldehyde than those of nonsmokers.

In low concentrations, formaldehyde and other chemicals that release formaldehyde can be found in cosmetics and other personal care products such as lotions, shampoos, conditioners, shower gels, and some fingernail polishes. In some cases, these may increase the concentration of formaldehyde in the air inside the room for a short period of time, but the levels reached are far below those considered hazardous.

Formaldehyde or formaldehyde-releasing chemicals are found in professional keratin hair smoothing treatments. Using these can raise indoor air formaldehyde concentrations to levels that could pose a health risk.

Employees in industries that make 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. Formaldehyde is mainly inhaled or absorbed through the skin in the form of gas or vapor. In one large study of formaldehyde-producing or -using industries, the average formaldehyde exposure level was 0.45 parts per million (ppm), with less than 3% of workers experiencing exposure levels above 2 ppm on average.

Can formaldehyde cause cancer?

In laboratory test animals, formaldehyde has caused cancer. In medical and occupational settings, formaldehyde exposure is associated with some types of cancer in humans, but the effects of exposure to small amounts are unclear.

Studies in the lab

Inhaled formaldehyde has been linked to cancers of the nasal cavity and leukemia in rats. The consumption of formaldehyde-containing water resulted in an increase in stomach tumors in one study, while no increase in any tumor or cancer was found in another.

A 10% solution of formaldehyde applied to mice's skin was linked to faster development of cancers caused by another chemical.

Studies in people

Inhaling formaldehyde at a concentration of 1.9 parts per million (ppm) for 40 minutes did not raise blood levels of formaldehyde.

Studies of people exposed to formaldehyde in the workplace have reported a link between formaldehyde exposure and nasopharyngeal cancer, but this outcome has not been observed in other studies. Workers in occupational settings that use or make formaldehyde and formaldehyde resins, as well as embalmers, were studied.

Additionally, studies of people exposed to formaldehyde at work have found a possible link to nasal sinus cancer.

Medical professionals who use formaldehyde, particularly myeloid leukemia, have been found to have an increased risk of leukemia. Formaldehyde exposure has also been linked to an increased risk of leukemia in certain studies, but not all studies have shown an increased risk.

Researchers have not found a consistent relationship between workplace exposure to formaldehyde and other types of cancer.

Workers exposed to formaldehyde had higher than normal levels of chromosome changes in their early white blood cells. The finding indicates a possible link between formaldehyde exposure and leukemia.

What expert agencies say

The environmental environment is studied by a variety of agencies (national and international) for its potential to cause cancer. Carcinogens are substances that cause cancer or promote cancer growth. The American Cancer Society looks to these organizations for evaluation of the risks based on research in laboratories, animals, and humans.

Some of these expert agencies have evaluated the cancer-causing potential of formaldehyde based on the available evidence.

The National Toxicology Program (NTP) is made up of several 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). Formaldehyde is a known human carcinogen, according to the NTP.

WHO's International Agency for Research on Cancer (IARC) is part of the organization. The agency identifies causes of cancer. Based on higher risk of leukemia and nasopharyngeal cancer, the IARC concluded that formaldehyde causes cancer in humans.

There is an electronic database maintained by the Environmental Protection Agency (EPA) known as the Integrated Risk Information System (IRIS), that contains information about human health effects caused by exposure to various substances in the environment. Formaldehyde is classified as a probable human carcinogen by the EPA.

Researchers from the National Cancer Institute have concluded that formaldehyde exposure may cause leukemia, particularly myeloid leukemia, in humans, based on studies in people and lab research.

See Known and Probable Human Carcinogens for more information about some of these agencies' classification systems.

Does formaldehyde cause any other health problems?

Those exposed to formaldehyde at levels higher than 0.1 parts per million (ppm) may experience health effects, including:

• eye irritation
• burning sensations of the eyes, nose, and throat
• coughing
• wheezing
• nausea
• skin irritation

Formaldehyde can cause severe reactions in some people, while it does not in others.

Formaldehyde in consumer products such as cosmetics and lotions may cause an allergic reaction in the skin (allergic contact dermatitis), which may cause an itchy, red rash that becomes raised or blistered.

How can I limit my exposure to formaldehyde?

In the home

In order to limit formaldehyde exposure in the home, the EPA recommends using pressed-wood products that are rated for exterior use. As phenol resins are used instead of urea resins, these products emit less formaldehyde. Ask before purchasing pressed-wood products, such as building materials, cabinetry, and furniture, whether the products contain formaldehyde.

You can also reduce the amount of formaldehyde in your home by not smoking inside and by ensuring adequate ventilation (such as using your stove vent fan), moderate temperatures, and reduced humidity levels through the use of air conditioners and dehumidifiers.

People who are concerned about formaldehyde exposure from personal care products and cosmetics can avoid using products that contain or release formaldehyde. Still, because the amount of formaldehyde released from these products is low, it isn’t clear that this will provide any health benefit.

Formaldehyde can be listed on a product label by other names, such as:

• Formalin
  
• Formic aldehyde
• Methanediol
• Methanal
• Methyl aldehyde
• Methylene glycol
• Methylene oxide
• Some chemicals that are used as preservatives can release formaldehyde, such as:
• Benzylhemiformal
  
• 2-bromo-2-nitropropane-1,3-diol
• 5-bromo-5-nitro-1,3-dioxane
• Diazolidinyl urea

1,3-dimethylol-5,5-dimethylhydantoin (or DMDM hydantoin)

• Imidazolidinyl urea
• Sodium hydroxymethylglycinate
• Quaternium-15

In the workplace

The US Occupational Safety and Health Administration (OSHA) has established limits for the amount of formaldehyde that workers can be exposed to at their place of work. At present the limit is at 0.75 ppm on average over an 8 hour workday. The highest concentration that a worker can be exposed to is 2 ppm, and that can only occur over 15 minutes. Employers must monitor formaldehyde levels and provide respirators and protective clothing as needed to limit exposure. This includes workers in any workplace where formaldehyde exposure is likely, including hair salons that use commercial hair smoothing products that release formaldehyde.