Formaldehyde Exposure and Human Health Risks

Abstract This chapter primarily focuses on the human health effects of formaldehyde inhalation exposure. It summarizes significant published findings and recently peer‐reviewed health risk assessments of national and international organizations on formaldehyde exposure including current regulatory standards. Formaldehyde is a flammable gas at room temperature and is found in consumer products and used in manufacturing processes, such as resins in composite wood products. Environmental exposure to formaldehyde can occur via inhalation, dermal, and ingestion routes. The most common route of formaldehyde exposure is inhalation resulting from breathing formaldehyde‐contaminated air. Formaldehyde enters the environment from natural and anthropogenic combustion sources, industrial on‐site releases, and off‐gassing of products containing formaldehyde. Acute and chronic exposures to formaldehyde through home furnishings, environmental contamination, cosmetics, and indoor and outdoor air pollution poses potential public health risks. Epidemiological, clinical, and experimental animal studies have shown that formaldehyde exposures are associated with potentially adverse human noncancer health outcomes. The epidemiologic evidence has shown an association between formaldehyde exposure and nasopharyngeal cancer as causal in human studies. Positive associations between formaldehyde exposure and lymphohematopoietic cancers have been reported for chemical workers, embalmers, anatomists, and pathologists. The mode(s) or mechanism(s) of formaldehyde exposure and reported cancers are not well understood; however, its exposure has been shown to be associated with the key events related to carcinogenicity.