Diazolidinyl urea (CAS# 78491-02-8) is a common, broad-spectrum antimicrobial preservative in cosmetics, known as a formaldehyde releaser that prevents bacterial and fungal growth, extending product shelf life, but can cause allergic reactions in sensitive individuals, requiring careful labeling and regulation. Its chemical formula is C8H14N4O7 and it appears as a white solid, releasing small amounts of formaldehyde to protect products from contamination. 
Diazolidinyl Urea Chemical Properties
| Boiling point | 421.04°C (rough estimate) |
| Density | 1.4734 (rough estimate) |
| Vapor pressure | 0Pa at 20℃ |
| Refractive index | 1.6590 (estimate) |
| Storage temp. | 2-8°C |
| Solubility | Water (Slightly) |
| Form | Solid |
| Pka | 11.22±0.46(Predicted) |
| Color | White to Off-White |
| Water Solubility | 1000g/L at 20℃ |
| Merck | 143,000 |
| Stability | Stable. Incompatible with strong oxidizing agents. |
| InChIKey | SOROIESOUPGGFO-UHFFFAOYSA-N |
| LogP | 0.9 at 20℃ |
| CAS DataBase Reference | 78491-02-8(CAS DataBase Reference) |
| EPA Substance Registry System | Diazolidinylurea (78491-02-8) |
Safety Information
| Hazard Codes | Xi |
| Risk Statements | 43 |
| Safety Statements | 36/37 |
| WGK Germany | 2 |
| RTECS | YS2717000 |
| HS Code | 29339900 |
| Toxicity | LD50 orally in rats: 2.57 g/kg; dermally in rabbits: >2.0 g/kg (Berke, Rosen) |
Product Application of Diazolidinyl Urea CAS#78491-02-8
Diazolidinyl urea is suitable for use in both leave-on and rinse-off formulations, including creams, lotions, shampoos, conditioners, liquid cosmetics, and eye makeup products. It has been officially approved for use in both the United States and the European Union. The typical recommended dosage ranges from 0.1% to 0.3%, and it is advisable to incorporate it at processing temperatures below 50 °C to maintain stability. For improved preservative performance, it can be used in combination with parabens and IPBC to achieve a synergistic antimicrobial effect.
