Formldehyde, also known as formalin, embalming fluid, or formol, is a colorless gas with a pungent odor. At high levels, formaldehyde is a probable human carcinogen. This fact sheet discusses formaldehyde, its uses, health threats from exposure, and ways you can minimize your exposure to the chemical.
The hemical formaldehyde (HCHO) is a preservative and a disinfectant. The family of formaldehyde chemicals are used in pressed wood products, urea-formaldehyde (UF) foam insulation, fixing tissue, embalming fluids, carpets, combustion appliances, clothing, and tobacco. Of all home products containing formaldehyde, pressed wood has the highest concentrations. Paneling, particle board, hardwood plywood, and particularly medium-density fiberboard are all glued with UF adhesives.
In the 1970s, the predominant use of formaldehyde in the home was in urea-formaldehyde foam insulation (UFFI). This type of insulation begins to deteriorate after exposure to high humidity and high temperatures and, in many homes, the levels of formaldehyde were high. In February of 1982, UFFI was banned by law. In 1983, the law was overturned, but the marketability of UFFI already had been destroyed.
The use of formaldehyde in other products is at a fairly low level. In fabrics, formaldehyde is used to bind pigments, as a fire retardant, and to create stiffness. In cottons and cotton blends, formaldehyde adds wrinkle resistance and water-repelling qualities. Because of its water resistance, formaldehyde is used in the manufacture of grocery bags, paper cups and plates, waxed paper, facial tissues, napkins, paper towels, and sanitary napkins. Formaldehyde is also used in cosmetics and fabric softeners. Combustion from gas stoves, gas or wood space heaters, and cigarettes also emits low levels of formaldehyde. Although burning products with formaldehyde does release very low levels of the gas, the amount of formaldehyde in these products is minimal and usually is not a concern.
Formaldehyde enters the environment through gradual release from the material. This passive release is called offgassing or outgassing. Because outgassing is gradual, the level of formaldehyde emitted from most manufactured products decreases over time. With pressed wood, the outgassing occurs rapidly, immediately after manufacture. Outgassing occurs more slowly during subsequent months or years as the glue breaks down. Newer products manufactured with formaldehyde have reduced levels of outgassing overall.
Formaldehyde is measured in parts per million (ppm) in the air. Most adults react to formaldehyde at a range of 0.5 to 1.5 ppm. Infants, the elderly, those with specific allergic reactions, and persons with respiratory problems may react to lower levels. Individual reactions to different levels of formaldehyde (as with most environmental stimuli) vary greatly based on hereditary and lifestyle factors. Symptoms of formaldehyde exposure include nausea, vomiting, abdominal pain, or diarrhea. When the reaction is allergic, symptoms may include minor respiratory irritation and watery eyes. Extreme cases of exposure or chronic exposure may be linked to respiratory cancer.
Symptoms of exposure are both immediate and severe. Unless the dosage is very large, the prognosis for recovery is very good. Even those who react severely recover. For less severe exposures, removing oneself from the area and a short amount of time can often suffice for treatment. For the average adult, a fatal dose is 30 millileters (ml).
The average formaldehyde level in remote outdoor locations is 0.002 to 0.006 ppm; in industrialized areas, the level averages between 0.01 and 0.05 ppm. In older conventional homes, formaldehyde readings average less than 0.05 ppm. In mobile homes, homes with a great deal of pressed wood, or homes with UFFI insulation, the range of formaldehyde may vary and has been identified at levels of 0.02 to 4 ppm.
If you suspect formaldehyde may be present at a threatening level in one of your environments, first have the air tested. Check the yellow pages for laboratories that would take such measurements. Some Realtors also have contacts with firms that conduct formaldehyde testing in the home.
A major step for mitigating any indoor air pollutant is to ensure proper ventilation within the home; a tightly sealed structure allows contaminants to accumulate. When possible, open windows and allow air to move through the structure. With carpets, clothing, and other small emitters, proper ventilation will control formaldehyde levels.
When the outgassing is from a specific source, control that source. With UFFI, for example, seal the containing walls. Use caulk or spackle to fill any holes and cracks. Check light switches and outlets for possible cracks as well. Good paint or vinyl wall coverings (such as wallpaper) can seal walls and reduce outgassing.
In extreme cases, a building can be treated with ammonia fumigation. This is a potentially dangerous process and should only be done by a laboratory with expertise in ammonia fumigation. Check the yellow pages for laboratories or services in your area.
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