Preservatives: Formaldehyde donors

Preservatives come in two main groups - the formaldehyde donors and the non-formaldehyde donors. Formaldehyde donors include DMDM hydantoin, diazolidinyl urea, imidiazolidinyl urea, and quaternium 15. Non-formaldehyde donors include everything else like phenoxyethanol and iodopropynyl butylcarbamate.

The formaldehyde donors are more water soluble than oil soluble, and work by decomposing slowly over the life span of our products to provide preserving powers. In general, the formaldehyde release increases with the pH of the product, as well as the temperature and length of time the product has been stored.

It's hard to make generalizations about the non-formaldehyde donors other than the fact that they don't donate formaldehyde.

Want to know more about the safety and regulations around formaldehyde donors? Then check out the Cosmetics Ingredient Review information here.

Join me in about an hour to take a look at organic acids we find in our preservatives.

A quick note: I'm getting confusing information about whether the parabens are formaldehyde donors or not! In the Handbook of Cosmetic Science & Technology (second edition) it notes (page 433 and on page 126 in the third edition) that "Preservatives can be divided into two groups, namely formaldehyde donors and those that cannot produce formaldehyde. The former group includes DMDM hyantoin, diazolidinyl urea, imidiazolidinyl urea, quaternium-15, and the parabens." It goes on to say on page 510, "Although formaldehyde has been one of the most popular and effective preservative, its use has declined as other compounds have come to the fore. Examples include methyl and propyl parabens, DMDM hyantoin, quaternium 15, imidiazolidinyl urea and others." So according to the Handbook of Cosmetic Science & Technology, parabens are formaldehyde donors.

But then I read in the Chemical and Physical Behaviour of Human Hair (page 198), "Among the commonly used preservatives that do not release formaldehyde are parabens..." I've checked other textbooks, including Cosmetic Dermatology: Principles & Practice, Hair in Toxicology, and The Principles & Practice of Contact and Occcupational Dermatology in Asia, and they all state that the parabens are NOT formaldehyde donors. So I'm going with this information - parabens are not considered formaldehyde donors.