Formaldehyde:

• is a colorless, flammable gas at room temperature,
• has a pungent, distinct odor, and
• may cause a burning sensation to the eyes, nose, and lungs at high concentrations.

Formaldehyde is a gaseous pollutant produced by both human activity and natural sources.

• Combustion processes account directly or indirectly for most of the formaldehyde entering the environment.
• Large amounts are produced in the United States during manufacturing processes and as components of many end-use products.
• Small amounts are produced naturally by plants, animals, and humans.

Formaldehyde can mostly be found in the air.

• Outdoor air releases include:
• power plants,
• manufacturing facilities, and
• automobile exhausts.

• Indoor air releases include:
• building materials,
• consumer products, and
• tobacco smoke.

Formaldehyde can also be found in rain water and surface water after release from the manufacture, use, and disposal of formaldehyde-based products.

• Manufacturing

Formaldehyde is widely used to make resins for wood products.

• Consumer products

Consumer products containing formaldehyde include (IARC 2006):

• antiseptics and cleaning agents,
• carpets and permanent press fabrics,
• cigarettes,
• cosmetics,
• fertilizers,
• insulation for electrical uses (i.e., wiring and appliances),
• manufactured wood products (i.e., furniture, plywood, particle-board),
• medicines and vitamins,
• paints and varnishes, and
• preserved foods.

These consumer oriented products mainly contain aqueous solutions of formaldehyde.

• Air

Formaldehyde is quickly broken down in the air, usually within hours.

• Water and soil

Formaldehyde in water may be broken down by bacteria or other microorganisms.

Formaldehyde evaporates from shallow soils.

The primary way you can be exposed to formaldehyde is by breathing air containing it. Releases of formaldehyde into the air occur from:

• industries using or manufacturing formaldehyde,
• wood products (i.e. particle-board, plywood, furniture),
• automobile exhaust,
• cigarette smoke,
• paints and varnishes, and
• carpets and permanent press fabrics.

Rural or suburban air generally contains lower concentrations of formaldehyde than urban air. Indoor air often contains higher levels of formaldehyde than outdoor air. Examples of concentrations of formaldehyde:

• 0.0002-0.006 parts per million (ppm) in rural and suburban outdoor air
• 0.0015-0.047 ppm in urban outdoor air
• 0.020-4 ppm in indoor air

A ppm in air represents the fraction of volume of air occupied by formaldehyde. 1 ppm is equivalent to 1 unit volume of formaldehyde per 1,000,000 units of air.

A large number of workers are potentially exposed to formaldehyde.

• The highest potential exposure occurs in the formaldehyde-based resins industry, where workers may be exposed to high air concentrations and also have dermal exposure from liquid formaldehyde.
• Other types of employees at risk for exposure to formaldehyde include:
• dentists,
• doctors,
• embalmers,
• nurses,
• pathologists,
• teachers and students who handle preserved specimens in laboratories,
• veterinarians, and
• workers in the clothing industry or in furniture factories.

Formaldehyde is occasionally detected in rain water and fogwater.

Formaldehyde has not been detected in soils, likely due to its high removal rate when released to soils.

Low levels of formaldehyde occur naturally in a variety of foods, such as fruits. Food may contain small amounts of formaldehyde from its use as a fumigant, fertilizer, or preservative.

• inhalation

When you breathe air containing formaldehyde, most of the formaldehyde is quickly broken down in the cells lining your respiratory tract and breathed out. Only at high levels does formaldehyde enter your blood.

• ingestion

Formaldehyde in food or water may also rapidly enter your body through the digestive tract.

• dermal contact

A very small amount may enter through your skin when you come into contact with liquids containing formaldehyde.

Once in your body, formaldehyde is rapidly broken down into other chemicals.

Most of these other chemicals quickly leave your body in the urine.

Formaldehyde can also be converted to carbon dioxide and breathed out of the body.

Workers and residents

• Inhalation

The most common health problems in people exposed to formaldehyde include irritation of the eyes, nose, and throat.

Formaldehyde may cause occupational asthma, but this seems to be rare.

Laboratory animals

• Inhalation

Animal studies have shown that inhalation of formaldehyde can result in irritation and damage to the lining of the nose and throat. High concentrations can also affect the lung.

Impaired learning and changes in behavior have been observed in rats after high concentrations of formaldehyde.

• Oral

Stomach damage has been observed in rats exposed to high oral doses of formaldehyde.

Some studies of humans exposed repeatedly to formaldehyde in workplace air found more cases of nose and throat cancer than expected. Animal studies of laboratory rats exposed for life to formaldehyde in air found that some rats developed nose cancer.

The Department of Health and Human Services (DHHS) and the International Agency for Research on Cancer (IARC) have characterized formaldehyde as a human carcinogen based on studies of inhalation exposure in humans and laboratory animals.

A small number of studies have looked at the health effects of formaldehyde in children. It is very likely that breathing formaldehyde will result in nose and eye irritation (burning feeling, itchy, tearing, and sore throat). We do not know if the irritation would occur at lower concentrations in children than in adults.

There is some evidence of asthma or asthma-like symptoms for children exposed to formaldehyde in homes.

Studies in animals suggest that formaldehyde will not cause birth defects in humans.

Formaldehyde is a component of tobacco smoke.

Avoid smoking in enclosed spaces such as inside the home or car in order to limit exposure to children and other family members.

Formaldehyde is released into indoor air from construction materials and a variety of consumer products.

• Formaldehyde levels can be reduced by bringing fresh air into the home.
• Limit the use of pressed wood in homes or seal uncovered pressed wood products.
• Families should keep houses well ventilated by opening windows or using ventilation fans when levels are known to be high.

Some permanent press fabrics emit formaldehyde.

• Washing these new clothes before wearing them will usually lower the amount of formaldehyde released from permanent press fabrics and reduce exposure to families.

Formaldehyde cannot be reliably measured in blood, urine, or body tissues following exposure. Formaldehyde is produced in the body and would be present as a normal constituent in body tissues.

Antibodies to formaldehyde-bound proteins can be found in the blood of people exposed to formaldehyde; however, this test cannot be used to determine the extent of exposure or the kind of health effects that might develop from exposure.

The EPA has determined that lifetime exposure to 1 ppm formaldehyde in drinking water is not expected to cause any adverse effects.

The EPA has also determined that exposure to formaldehyde in drinking water at concentrations of 10 parts per million (ppm) for 1 day or 5 ppm for 10 days is not expected to cause any adverse effects in a child.

OSHA set a legal limit of 0.75 ppm formaldehyde in air averaged over an 8-hour work day.

The U.S. Department of Housing and Urban Development (HUD) set standards for formaldehyde emissions in manufactured housing of less than 0.2 ppm for plywood and 0.3 ppm for particle board. The HUD standards are designed to provide an ambient level of 0.4 ppm or less in manufactured housing.