DIAZOLIDINYL UREA
Commonly Found In
Overview
Diazolidinyl urea is a broad-spectrum formaldehyde-releasing preservative marketed under the trade name Germall II. It releases more formaldehyde than imidazolidinyl urea and has a higher associated sensitization rate. The EU permits it at up to 0.5% with a mandatory 'contains formaldehyde' label if released formaldehyde exceeds 0.05%.
Also known as: Germall II, N-(hydroxymethyl)-N-(1,3-dihydroxymethyl-2,5-dioxoimidazolidin-4-yl)-N'-hydroxymethylurea
Key Benefits
Preservative only; no direct skin-conditioning benefit. Studies suggest higher formaldehyde release rate than imidazolidinyl urea, which corresponds to greater antimicrobial potency but also higher sensitization potential.
Supporting Research
- β’ CIR Expert Panel: Assessed diazolidinyl urea as safe at concentrations up to 0.5%
- β’ Frosch PJ et al. (1995): Higher patch-test sensitization rate compared to imidazolidinyl urea in dermatology patients
Skin Compatibility Ratings
Comedogenic Rating
Non-comedogenic; water-soluble preservative used at low concentrations (0.1β0.5%).
Source: CIR Expert Panel safety assessment
Irritancy Rating
Moderate irritancy/sensitization potential; releases more formaldehyde than imidazolidinyl urea; EU labeling required if released formaldehyde >0.05%
Source: CIR Expert Panel; patch-test literature
Typical Use Concentration
Range
0.1β0.5%
Optimal
0.1β0.3%
EU Annex V entry 46: max 0.5% with labeling. US: allowed; CIR assessed safe at β€0.5%.
Works Well With / Avoid
Works Well With
Use With Caution
EU Annex V max 0.5%; mandatory 'contains formaldehyde' label if released formaldehyde >0.05%. Higher formaldehyde release than imidazolidinyl urea; use minimum effective concentration.
Commonly Found In
Global Regulation Summary
Overview of current status across major international markets.
Detailed Regional Status
| Region | Status | Max Conc. | Conditions | Source |
|---|---|---|---|---|
| πͺπΊ EU | Allowed | - | - | Official β |
| πΊπΈ USA | Allowed | - | - | Official β |
| π―π΅ Japan | Allowed | - | - | Official β |
| π°π· Korea | Unknown | - | - | Official β |
| π¬π§ UK | Banned | - | Follows EU regulations (V/46) | Official β |
π Why Regulations Differ
EU and US both permit diazolidinyl urea at low concentrations with EU labeling requirements. Higher formaldehyde-release potential than imidazolidinyl urea results in better efficacy but increased sensitization risk.
Regulation Analysis
Regional Agreement
Banned in UK but allowed in EU, USA, Japan.
Category Comparison
There are 157 ingredients in the PRESERVATIVE category. 99% are banned in at least one major market.
Strictness Ranking
πΏ Natural Sources
Synthetic only. Not naturally occurring.
π How It's Made
Produced by reaction of allantoin with formaldehyde and urea, creating a more complex structure than imidazolidinyl urea. The resulting compound is N-[hydroxymethyl]-N-[1,3-dihydroxymethyl-2,5-dioxo-4-imidazolidinyl]-N'-[hydroxymethyl]urea.
π Uses in Cosmetics
Used at 0.1-0.5% as a preservative that works against a wide range of bacteria and mold. It slowly releases a tiny amount of formaldehyde to keep products fresh. The EU allows up to 0.5% with a required label warning about formaldehyde content.
π¬ Other Applications
Used in some topical pharmaceuticals, industrial emulsions, and water-based paints as a preservative.
π‘ Fun Facts
- β’ Introduced as Germall II by Sutton Laboratories in the 1970s as a more potent successor to Germall 115 (imidazolidinyl urea)
- β’ Studies show it can release 1-2% of its weight as free formaldehyde over time, making it one of the more significant formaldehyde-releasers
- β’ Despite being more effective than imidazolidinyl urea, its use has declined since the 2000s due to increased formaldehyde concerns
Data Sources
- β’ EU Cosmetics Regulation 1223/2009 Annex V entry 46
- β’ CIR Expert Panel β Safety Assessment of Diazolidinyl Urea
- β’ Frosch PJ et al. (1995) β Patch-test comparative sensitization data
Last data verification: 2026-04-16
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Frequently Asked Questions
What is DIAZOLIDINYL UREA used for in cosmetics?
DIAZOLIDINYL UREA is primarily used for preservative in cosmetic products. The ingredient is commonly found in various cosmetic products to prevent microbial growth.
Which countries regulate DIAZOLIDINYL UREA?
DIAZOLIDINYL UREA is banned in UK. The ingredient is freely allowed in EU, JP, US.
Are there alternatives to DIAZOLIDINYL UREA?
Due to regulatory restrictions on DIAZOLIDINYL UREA, cosmetic manufacturers often use alternative ingredients with similar functions. For preservative, alternatives may include other approved ingredients in the same category. Consult product labels for specific formulations, and look for products compliant with your region's regulations.
Where can I find official regulation information about DIAZOLIDINYL UREA?
Official information about DIAZOLIDINYL UREA regulations can be found on government websites: EU CosIng database, US FDA Cosmetics page, Japan MHLW cosmetics standards, UK Government cosmetics guidance, and Korea MFDS. Always verify regulatory status with these official sources before making formulation decisions.
Disclaimer
The information on this website is for educational and informational purposes only and is not intended as medical advice. While we strive for accuracy based on official government databases, cosmetic regulations change frequently. Always consult with a qualified professional or refer to the latest official regulatory documents for compliance. We are not responsible for any actions taken based on the information provided here.