Formaldehyde is a flammable and colourless gas with a pungent odour. It may also be referred to as formalin or methanal. There are numerous other synonyms and product names; see the HSDB for more information.
Formaldehyde is classified by IARC as Group 1, carcinogenic to humans, on the basis of sufficient evidence of carcinogenicity in humans and experimental animals. Epidemiological studies reviewed by IARC demonstrated consistently strong evidence that formaldehyde causes nasopharyngeal cancer in humans; strong, but not sufficient, evidence that occupational exposure to formaldehyde causes leukemia; and limited evidence that formaldehyde exposure causes sinonasal cancer. A recent IARC review of Group 1 carcinogens reaffirmed this classification, with new, sufficient evidence for leukemia.
Additional health effects of exposure to formaldehyde include respiratory and eye irritation and contact dermatitis.
Formaldehyde was not included in other Canadian government chemical listings reviewed.
Formaldehyde is used primarily in production of chemical intermediates (i.e. urea-formaldehyde resins, phenolic resins, etc.) for adhesives and binders in the wood products, pulp and paper, and synthetic vitreous fibre industries. In the wood industry, formaldehyde-based resins are used to make oriented strand board and other wood products. It is also used in the production of plastics and coatings, in textile finishing, and in the manufacture of various industrial chemicals.
As an aqueous solution, formaldehyde is an effective disinfectant and preservative that may be used in hospital wards, pathology labs, and funeral homes (as an embalming fluid). It is also used as a germicide, insecticide, and fungicide. As an antibacterial agent, it is found in soaps, shampoos, hair preparations, deodorants, lotions, cosmetics, mouthwash, and nail products.
Canadian Production and Trade
Production and Trade
Export: Mainly to the US
6,200 t of ‘methanal (formaldehyde)’
Import: Mainly from the US
12,730 t of ‘methanal (formaldehyde)’
t = tonne
Inhalation is the main route of exposure for formaldehyde. Low level exposure may also occur via dermal absorption or ingestion. CAREX Canada estimates that approximately 152,000 Canadians are exposed to formaldehyde in their workplaces. Currently, the 3 most important sources of formaldehyde exposure include decomposition of formaldehyde-containing resins, emissions from solutions (e.g. embalming fluid), and combustion sources (e.g. vehicle exhaust).
Although exposure to formaldehyde has decreased over time, exposure still occurs in a wide variety of occupations and industries. The wood product manufacturing and hospital industries are among the largest exposed industrial groups in Canada. In terms of occupations, the largest groups of workers exposed to formaldehyde are furniture and fixture assemblers.
In wood panel manufacturing, formaldehyde is released when heating adhesives, which can expose press operating and maintenance workers. In furniture manufacturing, formaldehyde is released during the preparation and application of varnishes or paints (especially when applied with a spray gun), and drying. Therefore, painters, manual labourers working at the dryers, and maintenance workers can also be exposed.
Other occupations with acute exposure to formaldehyde include cooks, embalmers, pathology lab workers, wood, pulp and paper processing workers, as well as health care professionals (nurses, dentists, and pharmacists) exposed during the use or clean-up of medical products and equipment.[2, 12]
Workers involved in the production of resins, man-made vitreous fibres and plastic products are potentially exposed to formaldehyde. Levels are expected to be low, however, because of improved ventilation and the development of resins that release less formaldehyde.
The biggest source of environmental formaldehyde is combustion and combustion by-products from power plants, incinerators, refineries, wood stoves, kerosene heaters, cigarettes, photochemical oxidation of hydrocarbons and other formaldehyde precursors, and forest fires.[2, 12]
Other sources include vent gas and waste water from formaldehyde production, vehicle exhaust, and off-gassing from formaldehyde-containing products (e.g., fumigants, soil disinfectants, embalming fluid, leather tanning agents, building material resins, wood products and building materials, and resin-treated fabrics and paper).[2, 12]
CAREX Canada estimates that formaldehyde levels in outdoor air are not likely sources of elevated cancer risk (low data quality). However, environmental estimates for formaldehyde levels in indoor air are associated with elevated cancer risk (low to moderate data quality).
Historically, the use of urea formaldehyde foam insulation (UFFI) resulted in potentially high concentrations of formaldehyde in homes (UFFI was banned in Canada in 1980).
For more information, see CAREX Canada’s environmental exposure estimates for formaldehyde. Searches of environmental and consumer product databases yielded the following results on current potential for exposure to formaldehyde in Canada:
NPRI and US Household Products Database
Search term: ‘formaldehyde'
Released into Environment
Wood and forest products; pulp and paper (133 facilities)
Sent to off-site recycling
US Household Products 2013
Glues, insulations, baby and pet shampoos, hand soap, aquatic plant fertilizers
t = tonne
Our team has performed a detailed scan of exposure control resources and assembled a compilation of key publications and resources. These are organized by type of exposure (environmental or occupational) and by specificity (general or carcinogen-specific). Please visit our Exposures Reduction Resources page to view.
We also recommend exploring the Prevention Policies Directory, a freely-accessible online tool offering information on policies related to cancer and chronic disease prevention. Providing summaries of the policies and direct access to the policy documents, the Directory allows users to search by carcinogen, risk factor, jurisdiction, geographical location, and document type. To learn more about policies specific to formaldehyde on the Directory, click here. For questions about this resource, please contact Michelle Halligan, from the prevention team at the Canadian Partnership Against Cancer.