Formaldehyde is a contaminant that has been categorized by the U.S. Environmental Protection Agency (EPA) as a hazardous air pollutant (HAP)1. It is a colorless, pungent-smelling gas that is found both indoors and outdoors. However, formaldehyde levels are usually higher indoors than outdoors because of the numerous sources within buildings. This could represent a health threat since we spend most of our time inside buildings and formaldehyde has been associated with respiratory problems and cancer.
Although formaldehyde occurs from natural processes, the high levels that humans are exposed to are due to man-made products. This air pollutant is mostly used in the production of urea-formaldehyde (UF) and phenol-formaldehyde (PF) resins. These resins serve as binders or adhesives in pressed-wood products. Urea-formaldehyde is commonly used in hardwood plywood, particleboard, and medium density fiberboard (MDF). Among these, MDF is usually the highest formaldehyde-emitting pressed wood product2. Furniture, cabinetry, shelving, and floor underlayment tend to use UF based wood products. Phenol-formaldehyde is typically found in pressed-wood products that are for exterior construction such as softwood plywood and oriented strand board (OSB). In general, wood products that contain PF emit considerably lower rates of formaldehyde than those with UF2.
There are numerous indoor sources of formaldehyde in addition to those that are wood-related. Household products that emit formaldehyde include permanent-press fabrics, glues and adhesives, and fingernail hardeners. Moreover, this air contaminant is also used as preservative in some paints, coatings, and cosmetics. Formaldehyde is also a byproduct of combustion, and is generated when burning wood, kerosene or natural gas, and by automobiles and cigarettes5.
Exposure to formaldehyde can cause various health effects that depend on the concentration levels and the individual. The International Agency for Research on Cancer (IARC) classified formaldehyde as a known human carcinogenic given the strong association between industrial workers exposed to formaldehyde and nasopharyngeal cancer3. Furthermore, the IARC determined that there is strong but not sufficient evidence of an association between leukemia and high exposures to formaldehyde3. Individuals who are exposed to lower levels of formaldehyde may experience watery eyes, irritation of the eyes and throat, nausea, difficulty in breathing, skin rash, and exacerbation of asthma2,4. Formaldehyde exposure can also induce allergy-like symptoms in people with chemical sensitivities.
The following are a few suggestions on how to reduce indoor formaldehyde levels2,4.
For more information on formaldehyde and the associated health effects, contact: