1H-imidazole is an imidazole tautomer which has the migrating hydrogen at position 1.
Definition
1H-imidazole is an imidazole tautomer which has the migrating hydrogen at position 1. It is a conjugate base of an imidazolium cation. It is a conjugate acid of an imidazolide. It is a tautomer of a 4H-imidazole.
Source: PubChem
US FDA substance register · UNII 7GBN705NH1 · registered name Imidazole · single chemical substance
Imidazole is the organic compound that conforms to the formula:
Cosmetic roles
Safety & regulatory references
- Banned
- ASEAN · China · European Union · United Kingdom
Source: ASEAN Cosmetic Directive · EU Cosmetics Regulation · MFDS (Korea) cosmetic regulatory information · UK cosmetics regulations (OPSS)
Not classified under Korea’s toxic-substance GHS list · existing chemical substance
EU Cosmetics Regulation, Annex II (prohibited substances), entry 1589
Restriction II/1589
Source: EU CosIng ingredient list
More data — names, identifiers, properties, test records, literature
Names & identifiers
- CAS No.chemical registry number
- 288-32-4
- EC No.EU chemical inventory number
- 206-019-2
- EC No.EU chemical inventory number
- 209-019-2
- DTXSIDUS EPA chemical ID
- DTXSID2029616
- DTXCIDUS EPA compound ID
- DTXCID809616
- IUPAC
- 1H-Imidazole
- Molecular formula
- C3H4N2
- Molecular weight
- 68.079 g/mol
Measured properties
- Appearance
- Liquid, Other Solid · Solid, [Merck Index] Colorless to yellow solid with an amine-like odor, [OECD SIDS] White or light yellow crystals, [Sigma-Aldrich MSDS]
- Odour
- Amine-like odor
- Boiling point
- 257 °C · 268 °C
- Melting point
- 90.5 °C · 89.52 °C
- Solubility
- Very soluble in water · In water, 241 g/100 g at 20 °C
- Density
- Density: 1.0303 g/cu m at 101 °C · Relative density (water = 1): 1.03
- Stability
- Stable under recommended storage conditions.
- Viscosity
- 2.617 mm²/s at 100 °C
- pH
- pH 10.5 for 38 g/L at 20 °C · 9.8 ()
- Dissociation constant
- 6.95 (at 25 °C) · pK 6.92 at 25 °C (weak base)
- Melting/freezing point
- 90 ℃
- Initial boiling point and range
- 257 ℃
- Flash point
- 145 ℃
- Vapour pressure
- 0.0462 ㎜Hg (at 25℃)
- Vapour density
- 2.36
- Relative density
- 0.6 ()
- n-Octanol/water partition coefficient (Kow)
- -0.08
- Auto-ignition temperature
- 480 ℃
- Molecular weight
- 68.08
Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.
Source: PubChem · KOSHA safety data sheets (Korea)
What products actually use it for
What the 8 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.
- Processing aids not otherwise specified2
- Catalyst2
- Chemical reaction regulator1
- Hardener1
- pH regulating agent1
- Intermediate1
Source: US EPA CompTox dashboard
Irritation and sensitisation studies
5 skin studies and 3 eye studies are on record.
The study conclusions largely agree (100%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.
See all 8 studies
- Classification not possible
Skin Sensitization · Screening - Skin Corr. 1C
Skin Irritation · Authoritative - Corrosive
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) equivalent or similar to - Category 1
Skin Irritation · Screening - Category 8.2C (Category 1C)
Skin Irritation · Read Across - Category 8.3A (Category 1)
Eye Irritation · Read Across - Corrosive or Irritation Persists for > 21 days
eye irritation: in vivo · Screening · OECD Guideline 405 (Acute Eye Irritation / Corrosion) equivalent or similar to - Category 2A
Eye Irritation · Screening
Source: US EPA CompTox dashboard
Related literature
- Contact dermatitis from topical imidazole antifungals: 15 new cases · 1989
- Structural Basis for EGFR Mutant Inhibition by Trisubstituted Imidazole Inhibitors · 2020
- Imidazole inhibits B16 melanoma cell migration via degradation of β‐catenin · 2010
- Studies on the Sensitizing Capacity of Imidazole Derivatives · 1990
- [The activity of imidazole derivatives in the presence of human plasma (author's transl)]. · 1981
Linked databases 24
- ASEAN Cosmetic Directive
- Australian Industrial Chemicals Inventory (AICIS)
- ChEBI
- ChEMBL
- China inventory of existing ingredients (IECIC)
- EU CosIng ingredient list 2
- EU Cosmetics Regulation
- EU prohibited substances (Annex II)
- Korea Cosmetic Association ingredient dictionary
- Korea toxic substances GHS register (NIER)
- KOSHA safety data sheets (Korea)
- MFDS (Korea) cosmetic ingredient register 2
- MFDS (Korea) cosmetic regulatory information 2 3
- NIST Chemistry WebBook
- PubChem 2
- Tlooto literature search 2 3 4 5
- UK cosmetics regulations (OPSS)
- UniChem cross-reference IDs
- US EPA CompTox dashboard 2
- US EPA DSSTox chemical database
- US FDA substance registration (GSRS)
- US FDA Unique Ingredient Identifier (UNII)
- Wikidata
- Wikipedia · Korean · English · Japanese · Chinese