• Formaldehyde (CH2O) is a colorless gas. It is irritating and has a sharp odour. Formaldehyde is widely produced around the world for use as a disinfectant and preservative. It is also used in textile finishing and in the production of resins that act as adhesives and binders for wood products, pulp, paper, glasswool and rockwool, as well as some plastics, coatings, paints and varnishes, and industrial chemicals.
• Formaldehyde also enters the Canadian environment through natural sources (e.g., forest fires) and certain human activities, such as smoking tobacco, burning automotive and other fuels, and residential wood burning.

How Formaldehyde Gets into the Air inside Canadian Homes

Sources of formaldehyde in indoor air include tobacco smoke, and smoke that may leak from wood-burning appliances, such as wood stoves and fireplaces.

Also, many of the products found inside Canadian homes contain and release very small amounts of formaldehyde into the air. Examples include:

• furniture, cabinets and building materials made from particleboard, medium density fibreboard and certain moulded plastics;
• consumer products, including some latex paints, wallpapers, cardboard and paper products, dishwashing liquids, fabric softeners, shoe-care agents, carpet cleaners, glues, adhesives, lacquers and some cosmetics, such as nail polish and nail hardener;
• some permanent press fabrics (e.g., certain curtains, sheets, clothing, etc.).

As a result of releases from these sources, formaldehyde is present at low levels in all Canadian buildings. For example, in 2002-2003, Health Canada measured levels of formaldehyde in the air inside a number of homes in Prince Edward Island and in Ottawa. The levels ranged from roughly 2 to 81 parts per billion (ppb).

The Health Effects of Formaldehyde

Formaldehyde causes cancer of the nasal cavity in laboratory animals and in workers exposed to formaldehyde in their jobs, but only at very high levels of exposure (thousands of ppb, or higher). The levels of formaldehyde in Canadian homes are well below levels of concern for cancer.

Exposure to moderate levels of formaldehyde (hundreds of ppb or greater) can cause a number of irritant symptoms, including temporary burning of the eyes or nose, and a sore throat.

Some studies have suggested that people exposed to formaldehyde levels ranging from 50 to 100 ppb for long periods of time are more likely to experience asthma-related respiratory symptoms, such as coughing and wheezing. The evidence for such effects is not conclusive.