What is it?
Diazolidinyl urea is a preservative predominantly cosmetic products, protecting them from bacteria, yeast, and mold growth. Although preservatives rarely cause allergies and irritations, they are a way to ensure that our cosmetics and personal care products are safe. Without them, products can spoil or become contaminated with bacteria.  

It is found primarily in cosmetic products.

How can I avoid it?
Skin contact with diazolidinyl urea is required for it to cause a rash. Discontinuation of exposure to products containing diazolidinyl urea should result in improvement and/or resolution of your dermatitis. The most common cause of allergic contact dermatitis from diazolidinyl urea is cosmetics preserved with this chemical. By law, all products made in the U.S. for topical use have the ingredients listed either on the product package or the box that contains it, so check the labeling of ingredients in your cosmetics. At work, request a Safety Data Sheet (SDS) to help identify potential sources of exposure.

Some individuals who are allergic to formaldehyde are also sensitive to diazolidinyl urea, since diazolidinyl urea releases small amounts of formaldehyde. Diazolidinyl urea sensitive individuals may need to avoid preserved with formaldehyde or formaldehyde-releasing agents, such as:

  • DMDM hydantoin (Glydant)
  • Imidazolidinyl urea (Germall)
  • 2-bromo-2-nitropropane-1,30diol (Bronopol)
  • Quaternium-15
  • Tris nitromethane (Tris Nitro) Tris Nitro is an industrial biocide and is not usually found in skin, hair or cosmetic product
Here is a partial list of products known to have contained Diazolidinyl Urea in the past.
  • Skin care products/Cosmetics
  • Anti-aging treatment
  • Aftershave
  • Baby wipes
  • Body wash
  • Bubble baths
  • Dentries and mouthwash
  • Facial cleanser
  • Hair care products
  • Hair colorants/“Permanents-relaxers”
  • Make-ups
    • Blush
    • Concealer
    • Eyeliner
    • Eyeshadow
    • Face powder
    • Foundation
    • Lipstick
    • Moisturizers/Lotions/Serums
    • Powders/Sprays
    • Shampoos/Conditioners
    • Shaving products
    • Soaps/Cleansers/Household detergents
    • Sunscreens
  • Medications, topical, prescription and over the counter such as
    • Anesthetics
    • Antiseptics
    • Creams, ointments, solutions
    • Foot and other powders
    • Nasal decongestants
    • Wound dressings
  • Industrial
    • Cutting fluids
    • Cleansers
    • Liquid soaps
    • Cleaning agents
  •  Pet shampoos
  •  Used to “brown” baked goods (pretzels)
Other names for diazolidinyl urea:
  • Germall II
  • N,N1—Bis (hydroxymethyl) urea
  • N-(hydroxymethyl) N-1,3 dihydroxymethyl-2,5-dioxo-4-imidazolidinyl-N-(hydroxymethyl) urea
  • Germaben II (mixture)
Potential cross-reacting/co-reacting substances:
  • Formaldehyde
  • Quaternium-15
  • Imidazolidinyl urea
  • DMDM hydantoin
  • 2-bromo-2-nitropropane-1,30diol (Bronopol)
  • Sodium Hydroxymethylglycinate

How safe is it?

Hang tight. We're thinking.