Formaldehyde is a common cause of indoor air pollution that many people are not aware of. Formaldehyde has a distinctive smell and is instantly recognizable in high concentrations, but can go unnoticed in smaller amounts. It has been linked to cancer in animal studies and is believed to be carcinogenic for humans as well.
Aside from cancer, formaldehyde can cause irritation in the throat, eyes, and nose, fatigue, coughing, wheezing, rashes, asthma attacks, or even a severe allergic reaction. It only takes a very tiny amount of formaldehyde in the air to cause such symptoms, above 0.1 parts per million (ppm).
Some of the lesser-known sources of formaldehyde include urea-formaldehyde foam insulation (UFFI), which homeowners may or may not be aware of. Tobacco smoke is another source of exposure for those who smoke and the people who live with them. Pressed wood products contain formaldehyde in their resin adhesive and these products include shelves, cupboards, furniture, flooring products, sub-flooring, and some types of wood paneling and wall decor.
Any sources of combustion, regardless of the type of fuel, can potentially create indoor air pollution with formaldehyde and other chemicals without proper use, maintenance, and ventilation. Certain glues used in construction contain it, as do durable press drapes and even perma-press clothing. It helps to air such clothing and drapes somewhere away from the living spaces in the house for a while to reduce formaldehyde exposure.
In older homes, products that contain formaldehyde release less formaldehyde into the air than they originally did and are thus typically emitting well under 0.1 ppm. But newer homes can have levels up to 0.3 ppm, particularly if they have many pressed wood products or other materials that contain formaldehyde.
To reduce formaldehyde exposure, homeowners should use air conditioning to keep the temperature levels and humidity down, since heat and humidity can increase the formaldehyde emissions. If you must use pressed-wood products, use those that are marked “exterior grade” as they contain phenol resins instead of urea resins. Finally, increase ventilation overall, especially when a new item or construction material containing formaldehyde comes into the home.