Formaldehyde is a colorless gas and a volatile organic compound (VOC), meaning it easily vaporizes and becomes airborne. This allows it to be present in the air, detectable even at low concentrations.
What Formaldehyde Smells Like
Formaldehyde possesses a distinctive, pungent odor, often described as sharp, irritating, and unpleasant. Many compare its scent to pickles, a sweetish, acrid chemical smell, embalming fluid, or new particleboard. The human nose is sensitive to formaldehyde, capable of detecting concentrations as low as 0.05 to 1.0 parts per million (ppm). This minimum concentration is known as the odor threshold. While the odor can serve as a warning, relying solely on smell is not always reliable. Some individuals may experience irritation below their ability to smell it, and prolonged exposure can lead to odor fatigue, where the nose adapts and no longer detects the smell.
Where You Might Encounter It
Formaldehyde is commonly found in everyday places and products, largely due to its use in manufacturing as an adhesive, bonding agent, and solvent. A significant source in homes is pressed-wood products like particleboard, plywood, and medium-density fiberboard, which use formaldehyde-containing resins. New furniture and cabinetry often emit formaldehyde through off-gassing, especially when new. Beyond wood products, it can be present in new carpets, certain glues, paints, foam insulation, and some personal care products like cosmetics, shampoos, and nail polish. Combustion byproducts are another source, including tobacco smoke, vehicle exhaust, and emissions from un-vented fuel-burning appliances like gas stoves and fireplaces.
Addressing the Odor
Detecting the smell of formaldehyde often indicates concentrations that can cause irritation. Short-term exposure can lead to irritation of the eyes, nose, and throat, causing symptoms like coughing, headaches, or a burning sensation. The first step to address the odor and reduce exposure is increasing ventilation. Opening windows and doors allows fresh air to circulate and helps dilute airborne formaldehyde. Using exhaust fans, especially in kitchens and bathrooms, can also help expel contaminated air.
Identifying and removing the source is also important. New furniture or building materials can be aired out in a well-ventilated space, such as a garage, before being brought indoors. Reducing indoor humidity can also help, as formaldehyde emissions increase with higher temperatures and humidity. Using dehumidifiers or air conditioning can help maintain optimal humidity between 30-50%. For persistent odors or health concerns, professional air quality testing can provide specific measurements.