Diazolidinyl Urea

Diazolidinyl urea is a synthetic ingredient produced by a reaction of allantoin and formaldehyde.

The primary function of this ingredient is as a preservative. It is not considered broad spectrum because it does not act against any type of yeast or mold.

However, it is effective against gram negative bacteria, such as E. coli, and gram positive bacteria, such as S. aureus. Therefore, it is commonly paired with antifungal preservatives to create a broad spectrum system, and these antifungal preservatives may include some types of parabens or iodopropynyl butylcarbamate for paraben-free systems.

Typical use levels of diazolidinyl urea are between 0.2 and 0.5 percent, which are fairly cost-effective levels. In addition, this ingredient is supplied as a white powder and is soluble in water-based systems, including lotions, creams, and skin cleansers that utilize only nonionic surfactants.

Anionic surfactants, including sulfosuccinates, amphoteric surfactants, such as cocamidopropyl betaine, and cationic surfactants, like behentrimonium chloride, will deactivate diazolidinyl urea – or make it ineffective against bacteria.

Otherwise, it is effective in a typical pH range of 3.0 to 8.5, and this pH range covers most skincare products.