IAQ Home Survey Formaldehyde


Formaldehyde is a colorless, strong-smelling gas often found in aqueous (water-
based) solutions. Commonly used as a preservative in medical laboratories and mortuaries, formaldehyde is also found in many products such as chemicals,
particleboard, household products, glues, permanent press fabrics, paper
product coatings, fiberboard, and plywood. It is also widely used as an industrial
fungicide, germicide and disinfectant. Formaldehyde is a sensitizing agent that
can cause an immune system response upon initial exposure. It is also a cancer
hazard. Acute exposure is highly irritating to the eyes, nose, and throat and can
make anyone exposed cough and wheeze. Subsequent exposure may cause
severe allergic reactions of the skin, eyes and respiratory tract. Ingestion of
formaldehyde can be fatal, and long-term exposure to low levels in the air or on
the skin can cause asthma-like respiratory problems and skin irritation such as
dermatitis and itching. Concentrations of 100 ppm are immediately dangerous to
life and health (IDLH). Note: The National Institute for Occupational Safety and
Health (NIOSH) considers 20 ppm of formaldehyde to be IDLH.

Formaldehyde concentrations can vary depending on environmental conditions such as temperature, humidity, and ventilation rate. As temperature and humidity increase, the formaldehyde concentration will increase and as the ventilation rate increases, the formaldehyde concentration will decrease.

Although there are no requirements set for formaldehyde concentration limits in homes, there are a number of recommendations that may be useful. Many organizations or government authorities suggest formaldehyde concentrations not exceed 100-120 ng/L (80-100 parts per billion or ppb) and 50-60 ng/L (40-50 ppb) for short term and longer term exposures, respectively. Some organizations or government authorities recommend more stringent levels for longer term exposures. In general, formaldehyde concentrations should be kept as low as reasonably achievable. Most homes measured by Prism's air test have concentrations in the range of 30 to 70 ng/L.

Major Health Effects of Formaldehyde Exposure

Health effects vary depending on the individual. Common symptoms of acute exposure include irritation of the throat, nose, eyes, and skin; this irritation can potentially exacerbate asthma symptoms and other respiratory illnesses. Long term, or chronic, exposure may also cause chronic runny nose, chronic bronchitis, and obstructive lung disease. In 2004, the International Agency for Research on Cancer (IARC) reclassified formaldehyde from "probably carcinogenic to humans" to "carcinogenic to humans" related to nasopharyngeal cancer. Since many factors are involved in the development of cancer, no definitive "safe level" of exposure has been established. The best way to reduce the risk of cancer is to limit exposure.

Formaldehyde Sources

There are many possible sources for formaldehyde in a home, although building products typically make up a large proportion of the concentration. Any recent renovation or new materials brought into the home is likely to increase the formaldehyde levels. The concentration will decrease over time as the materials off gas, so increasing the ventilation as much as possible is typically the best way to quickly decrease the formaldehyde in your home after recent renovation or installation of new materials.

· Products that contain urea-formaldehyde (UF) resins

         · particleboard, hardwood plywood paneling, medium density fiberboard

· Products that contain phenol-formaldehyde (PF) resins (lower concentrations of formaldehyde than UF resins)

· softwood plywood, flake or oriented strand board

· Pre-finished engineered flooring

· Insulation

· Glues and adhesives

. Paints and coatings

· Textiles

· Disinfectant cleaning products and soaps

· Preservatives

· Personal care products, especially certain hair products

· Cosmetics

· Pet care products

· Bactericides and fungicides

· Combustion byproduct (burning)

· Tobacco smoke and fuel-burning appliances (gas stoves, kerosene space heaters and fireplaces)

Formaldehyde is also produced naturally in living systems, e.g., trees and other plant life, and during decay and combustion processes. Formaldehyde is also involved in atmospheric processes. Outdoor concentrations of formaldehyde from both natural and man-made sources can range from less than 1 ng/L in remote areas to 10-20 ng/L in urban environments.


Additional Resources:

World Health Organization (WHO) Air Quality Guidelines for Europe, 2nd Edition (2000); pg 87-91

Europe: Report No. 7-Indoor Air Pollution by Formaldehyde in European Countries (1990)

Health Canada: Residential Indoor Air Quality Guideline-Formaldehyde US Consumer Product Safety Commission (CPSC)

Update on Formaldehyde (2013) Environmental Health (US) - Formaldehyde Exposure in Homes: A Reference Guide for State Officials to use in Decision Making

US Environmental Protection Agency: Formaldehyde US Agency for Toxic Substances and Disease Registry (ATSDR): Formaldehyde ToxFAQs™

US National Institutes of Health (NIH): ToxTown: Formaldehyde Chemical Reviews (Journal): Formaldehyde in the Indoor Environment Household Products Database: Formaldehyde