Common type of preservative found in cosmetics (Source: Contact Dermatitis
, December 2000, pages 339–343). Despite some claims, there is no higher level of skin reaction to formaldehyde-releasing preservatives than to other preservatives (Source: British Journal of Dermatology
, March 1998, pages 467–476). In fact, there is a far greater risk to skin from a product without preservatives, because of the contamination and unchecked growth of bacteria, fungus, and mold that can result if no preservatives are used. However, there is concern that when formaldehyde-releasing preservatives are present in a formulation that also includes amines, such as triethanolamine (TEA), diethanolamine (DEA), or monoethanolamine (MEA), nitrosamines can be formed, and nitrosamines are carcinogenic substances that can potentially penetrate skin (Source: Fundamentals and Applied Toxicology
, August 1993, pages 213–221). Whether or not that poses a health risk of any kind has not been established.