Formaldehyde is a colourless, pungent chemical used in a number of manufacturing and chemical industries, and as a preservative in many types of products. Formaldehyde is found, in at least low concentrations, in most homes and workplaces. Many products that use formaldehyde contain very small amounts and may cause problems only for the few people who suffer extreme sensitivities.
Air pollution is the greatest source of exposure to formaldehyde for the general population. Sources include cigarette smoke, emission from new plastic materials such as upholstery and carpets, pressed wood products and fuel-burning appliances. In house fires, formaldehyde residues in fabrics and foams play a major role in the toxicity of the smoke.
Industrial workers who produce formaldehyde or formaldehyde-containing products, laboratory technicians, certain health care professionals, and mortuary employees are at risk for high levels of exposure to this chemical. Exposure occurs from inhaling formaldehyde gas or vapour from the air or by absorbing liquids containing formaldehyde through the skin. However industrial hygiene measures are generally instituted to minimise exposure. The greatest risk for injury from formaldehyde is in workplaces with inadequate safety measures.
In 1980, laboratory studies showed that exposure to formaldehyde could cause nasal cancer in rats. In the following decades the United States (US) National Cancer Institute (NCI) and other research groups conducted studies to document potential links between formaldehyde exposure and increased risk of cancer among humans. These studies focused primarily on workplace exposures. Several studies have reported a link between formaldehyde exposure and cancer of the nasopharynx (the upper part of the throat behind the nose and near the base of the skull), but others have not. Some studies have suggested that formaldehyde exposure could be linked to lung cancer, however more recent research has not found evidence for such a link. Several NCI studies have found that anatomists and embalmers are at increased risk of leukaemia and brain cancer. One NCI study documented an increased risk of death due to lymphoma and leukaemia among a large sample of workers potentially exposed to formaldehyde. Additionally a USNational Institute for Occupational Safety and Health (NIOSH) study of textile workers found a link between the length of exposure to formaldehyde and death from leukaemia. However, a large study of British industry workers did not find a link between cumulative formaldehyde exposure and death from leukaemia. As a result of this research, in 2006 (and again in 2012) the International Agency for Research on Cancer (IARC) classified formaldehyde as carcinogenic (cancer causing substance) to humans. IARC is a part of the World Health Organisation which convenes international expert working groups to evaluate the evidence of the carcinogenicity of specific exposures. Additionally, in 2011, the US National Toxicology Program listed formaldehyde as a known human carcinogen in its 12thReport on Carcinogens.
To limit your formaldehyde exposure, Cancer Council NSW recommends that you reduce household formaldehyde exposure by not allowing smoking inside, washing new clothing before use, and ensuring adequate ventilation throughout the home. Before buying pressed wood products, such as building materials, cabinetry, and furniture, ask manufacturers about the products and purchase lower-emitting pressed wood products. After bringing new sources of formaldehyde into the home, increase ventilation – open windows and use fans to bring in fresh air. Employees who use formaldehyde in the workplace should strictly follow workplace industrial hygiene precautions.