Allergic Contact Dermatitis: Topical Preservatives, Part I

J. Desiree Douglas


Dermatology Nursing 

In This Article

Imidazolidinyl Urea

Synonyms for Imidazolidinyl Urea

  • Germall 115

  • Euxyl K 200 Abiol

  • Imidurea NF

  • N,N-Methylenebis

  • (N1-)-(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl urea

  • Sept 115

Imidazolidinyl urea is the second most common preservative used in cosmetic products (Marks et al., 2002; Sasseville, 2004). Imidazolidinyl urea affected 2.9% of patch test patients in 2005–2006 (Zug et al., 2009). This preservative is active against bacteria, including Pseudomonas aeruginosa (Maier et al., 2009). Imidazolidinyl releases 1/8 of the amount of formaldehyde that quaternium-15 releases (Rietschel & Fowler, 2008). Therefore, it is safer for patients with formaldehyde sensitivity. It is also nontoxic and nonirritating to the skin (Rietschel & Fowler, 2008). Cross reaction to diazolidinyl urea is possible (Marks et al., 2002). Imidazolidinyl urea is often combined with parabens to preserve products.

Sources of imidazolidinyl urea (Maier et al., 2009; Marks et al., 2002).

  • Cosmetics

  • Liquid soaps

  • Topical medications