Also known as: Urea, N-[1,3-bis(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl]-N,N'-bis(hydroxymethyl)-, Diazolidinylurea, N-(1,3-Bis(hydroxymethyl)-2,5-dioxo-4-imidazolidinyl)-N,N'-bis(hydroxymethyl)urea, EINECS 278-928-2, N-(Hydroxymethyl)-N-(1,3-dihydroxymethyl-2,5-dioxo-4-imidazolidinyl)-N'-(hydroxymethyl)urea (+2 more)
INCI: DIAZOLIDINYL UREA
Diazolidinyl Urea (CAS 78491-02-8) is a cosmetic preservative functioning as Preservative. Reported NOAEL =100 mg/kg bw/day in Rat (ECHA); EU Regulation 1223/2009 status: restricted, max 0.5% (face leave-on); 0.6% (rinse-off); 1 safety opinion reviewed (CIR Safety Assessment). Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety and pharmaceutical data.
View industrial chemical safety profile for CAS 78491-02-8 →
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Margin of Safety, dermal absorption, and sensitization profile summaries for Diazolidinyl Urea.
Calculate MoS for your specific formulation with the MoS Calculator.
3 study endpoints found for Diazolidinyl Urea. NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.
| Endpoint | Value | Route | Species | Study Type | Source |
|---|---|---|---|---|---|
| NOAEL | =100 mg/kg bw/day | oral | Rat | subchronic | ECHA |
| NOAEL | =300 mg/kg bw/day | dermal | Rat | developmental | ECHA |
| NOAEL | =500 mg/kg bw/day | oral | Rat | developmental | ECHA |
Official safety assessments from the Scientific Committee on Consumer Safety (SCCS) and Cosmetic Ingredient Review (CIR).
Urea along with the comments that were received. The Panel concluded that this ingredient could be safely used in cosmetic products at the minimum effective concentration. The effective use and safety test data indicate that the potential of this ingredient to produce adverse reactions should be min
Contact sensitization data for Diazolidinyl Urea based on clinical patch test studies and IFRA standards.
Source: FDA
Skin absorption and penetration characteristics of Diazolidinyl Urea, relevant to systemic exposure and MoS calculations.
Source: CIR Expert Panel
Cross-referenced EDC classifications, mechanism data, and dose-response evidence from EDLists, SIN List, and cosmetic-specific detail sources.
| Endpoint | Target | Value | Direction |
|---|---|---|---|
| ERα transcriptional activation (indirect via max HCHO release) | ERα (indirect via HCHO) | EC50/IC50: LOEC ~25 µM (estimated, highest HCHO releaser); LOEC: ~25 µM (estimated); NOEC: not established mixed | weak agonist |
| Thyroid peroxidase inhibition (indirect) | TPO (indirect via HCHO metabolite) | EC50/IC50: No direct IC50; activity scales with HCHO release (highest among tested FRPs); LOEC: not established; NOEC: not established mixed | inhibitor (indirect; highest HCHO release among FRPs) |
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
European Commission CosIng database Annex references per Regulation (EC) No 1223/2009.
Additional regulatory detail beyond the 7-jurisdiction summary: Saudi SFDA, Korea MFDS, ASEAN ACD, Japan/Korea, Brazil/India, and cross-jurisdictional restriction entries.
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| CN | permitted_preservative | 0.5 | All cosmetics |
| IN | permitted_preservative | 0.5 | all cosmetics |
| AU | restricted | 0.6 | preservatives |
| BR | permitted_preservative | 0.5 | - |
| ASEAN | permitted_preservative | 0.5% | All products |
Preliminary editorial summary for Diazolidinyl Urea — not a computed safety verdict. See the sourced toxicological data above.
Public NOAEL study rows linked to Diazolidinyl Urea by CAS number or substance name.
Same-CAS public records found in pharmaceutical data.
Same-CAS rows from the pharmaceutical spoke database.
Diazolidinyl Urea has a safety rating of "MODERATE" in our database. EU status: restricted. US status: restricted. 3 toxicological study endpoint(s) are available in our database. This ingredient has been reviewed by CIR Safety Assessment.
Diazolidinyl Urea EU regulatory status: restricted. Maximum allowed concentration: 0.5% (face leave-on); 0.6% (rinse-off). This is based on EU Regulation 1223/2009 and its amendments.
Diazolidinyl Urea functions as: Preservative. It is classified as a Preservative in our database. CAS number: 78491-02-8.
The NOAEL (No Observed Adverse Effect Level) for Diazolidinyl Urea is =100 mg/kg bw/day based on a subchronic study via oral route in Rat. A total of 3 study endpoints are available. Source: ECHA.
Diazolidinyl Urea also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
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