Substances referred to as formaldehyde releasers were identified on review of the literature. Information on product categories and typical concentrations for chemical products containing formaldehyde and formaldehyde releasers was obtained from the Danish Product Register Data Base (PROBAS). As of February 1992, 62,000 products were registered in PROBAS, 30,900 of these with information on composition and product category. Among the components of these products, 19 of the 22 identified formaldehyde releasers were found. The number of products registered with each formaldehyde releaser varied from 4 to 171, with cleaning agents, soaps, shampoos, paint/lacquers, and cutting fluids as the most frequent product categories. The most frequently registered formaldehyde releasers were bromonitropropanediol, bromonitrodioxane, and chloroallylhexaminium chloride. Formaldehyde itself was registered in 1,781 products, and was found in all product categories included in the study. It is concluded that products for industrial use as well as household and personal care products should be considered as sources of formaldehyde exposure. The use of unsystematic chemical names in literature is discussed.