Imidazolidinyl urea is a chemical that is used as a preservative and an antimicrobial in a wide range of cosmetic and other personal care products, according to Chemical Land 21. Imidazolidinyl urea accomplishes its antimicrobial action by gradually releasing formaldehyde.Continue Reading
Imidazolidinyl urea is the product of the chemical reaction between formaldehyde and allantoin in a heated sodium hydroxide solution, according to Wikipedia. The chemical is related to diazolidinyl urea, a product that is also used as a personal care product antimicrobial. Imidazolidinyl and similar chemicals are needed in the cosmetics and pharmaceutical industries because many products make use of biodegradable ingredients, notes Cosmetic Tests Labs. Without antimicrobial and preservation agents, these products can rapidly degrade and become unsafe for use.
Despite their benefits, imidazolidinyl urea and related chemicals can cause negative reactions such as dermatitis, warns Natra Care. This is particularly problematic because products said to be hypoallergenic may contain imidazolidinyl urea or other formaldehyde-releasing antimicrobials. Fortunately, alternative preservatives exist, according to Cosmetic Test Labs. These include parabens such as propylparaben and butylparaben, isothiazolinones such as kathon, organic acids such as benzoic acid and sorbic acid, and phenoxyethanols such as Optiphen Plus. The chemicals are sometimes combined for enhanced effectiveness. For instance, imidazolidinyl urea can be combined with parabens to better tackle gram-positive and gram-negative bacteria, while phenoxyethanols are often combined with potassium sorbate or caprylyl glycol to improve efficacy against a wide range of bacteria.Learn more about Chemistry