Imidazolidinyl Urea

SCA endorses products with the Allergy Certified logo that restrict usage of Imidazolidinyl Urea and Diazolidinyl Urea, to 1% or less. Due to Imidazolidinyl Urea being artificial, some respected doctors recommend avoiding it, this due to its synthetic properties & not toxicity.


Imidazolidinyl Urea CAS 39236-46-9. Diazolidinyl Urea CAS No: 78491-02-8. Synonym(s); Urea, N,N''-methylenebis[N'-[3-(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl]. Other names: N,N-methylenebis (N'-)1-(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl urea, Urea, N,N-methylenebis [N'-[3-(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl], 1,1'-Methylenebis[3-[3-(hydroxymethyl)-2,5-dioxo4 imidazolidinyl]urea], Germall 115®, Imidurea NF®, Biopure 100®, Imidurea®, Sept 115®, Tristat 1U®, Unicide U-13®


Human skin toxicant or allergen, antimicrobial preservative that works by forming formaldehyde in cosmetic products. Standard usage concentration of 0.2 to 0.4%, up to a maximum of 1 .O% - preservative in cosmetics and personal care products. Imidazolindinyl Urea is a formaldehyde-releasing preservative.

“Formaldehyde is a naturally occurring substance made of carbon, hydrogen and oxygen. Humans produce about 1.5 ounces of formaldehyde a day as a normal part of our metabolism. Inhaled formaldehyde is rapidly metabolized and ultimately converted to carbon dioxide and exhaled. Formaldehyde does not accumulate in the body.” - download the fact sheet by


Used in: foundations, powders, concealers. Eye makeup, eye liners, lotions, creams body powders, shadows, mascara, self tanning lotions, makeup removers, nail products, sunscreen, cleansers and topical medications.


  • "Typical allergic contact dermatitis reactions may occur, however, imidazolidinyl urea is not a common cause of contact allergy when compared with other preservatives. However, if you have sensitivity to imidazolidinyl urea, these products are far from being hypoallergenic and should be avoided." - DermNet NZ

  • NCBI "Contact allergy to diazolidinyl urea may or may not be due to formaldehyde sensitivity" -

  • "Discontinuation of use of products containing Imidazolidinyl Urea should result in improvement and/or resolution of your dermatitis. Imidazolidinyl Urea allergic patients should avoid this preservative by examining the ingredient labels before purchase. Imidazolidinyl Urea is frequently found in products that carry the ‘hypoallergenic’ label. Here is a partial list of products known to have contained Imidazolidinyl Urea in the past." -

  • "known for being non-toxic, non-irritating and a relatively non-sensitizing agent, but is a formaldehyde-releasing agent." -

  • "Imidazolidinyl urea is known to release formaldehyde, which is used globally by scientists and morticians in preserving corpses and body parts. Formaldehyde is toxic to humans and may cause many negative side effects." -

  • "The toxic preservative is also detrimental to bone and muscle health. According to experts, diazolidinyl urea exposure may raise the odds of joint and chest pain, fatigue and dizziness. The compound is also shown to trigger immune dysfunction and eye damage." -


FRPs Formaldehyde Releasing Preservatives

SCA campaigns for some FRP's to be excluded from Australian cosmetics, personal care and household products. Products endorsed by SCA exclude certan FRP's and restrict all preservatives to a maximum of <1% or less for leave on products and a maximum of <3% or less for rinse off products. FRP's should also require a warning on the product label to "always patch test before use". Standard use of preservatives ranges from 0.01 to 0.3% the percentage usage should vary according to the age of the consumer eg. baby products and those intended for sensitive allergy prone skin like eczema should not contain FRP's, FRP's should be restricted to a maximum of 0.1 to 1% or less depending on the age of the consumer.

"Oral products such as toothpastes may only contain up to 0.1 percent formaldehyde, while nail hardeners can have up to 5 percent. All other cosmetic products (such as shampoos and straightening solutions) can have up to 0.2 percent. At these lowlevels, the use of formaldehyde is deemed to be safe." -

"Formaldehyde is also produced naturally in the human body as a part of normal functions of the body to produce energy and build the basic materials needed for important life processes. This includes making amino acids, which are the building blocks of proteins that the body needs." - FDA

RESOURCES & RECOMMENDED ARTICLES: Formaldehyde in vaccines,

Amina Kitching