Solvent · low polarity
Benzene C6H6
Aromatic nonpolar solvent; historically a normal-phase (adsorption) HPLC mobile-phase component and a GC sample/diluent solvent, and the apex reference for Snyder selectivity group VII in the solvent-selectivity triangle. Its high UV cutoff (~280 nm) makes it unsuitable for UV detection. Now almost entirely avoided/banned in analytical labs and pharma processes because it is a Class 1 (avoid) residual solvent and a confirmed human carcinogen; usually replaced by toluene where an aromatic solvent is needed.
Compiled by Hemant RawatLast reviewed July 2026How we verify
Properties
- Formula
- C6H6
- CAS number
- 71-43-2
- UV cutoff
- 280 nm
- Snyder polarity index (P′)
- 2.7
- Selectivity group
- VII
- Eluotropic strength ε° (silica)
- 0.25
- Boiling point
- 80.1 °C
- Viscosity (25 °C)
- 0.6 cP
- Refractive index (nD²⁰)
- 1.5011
- Density
- 0.8765 g/mL
- Water miscibility
- immiscible
- USP <467> class
- Class 1
Safety
- flammable
- carcinogen (IARC Group 1, human)
- toxic
- reprotoxic (suspected)
- aspiration hazard
- CNS depressant / hematotoxic (bone marrow, leukemia)
Reference only. Solvents can be flammable, toxic, or peroxide-forming. Always consult the Safety Data Sheet (SDS) and your lab's protocols before handling.
What Benzene mixes with
Miscible with: 1-Propanol, 1,2-Dichloroethane, 1,4-Dioxane, 2-Propanol, Acetic acid, Acetone, Acetonitrile, Carbon tetrachloride, Chloroform, Cyclohexane, Dichloromethane, Diethyl ether, Dimethyl sulfoxide, Ethanol, Ethyl acetate, Iso-octane, Methanol, Methyl ethyl ketone, Methyl isobutyl ketone, MTBE, n-Butanol, n-Butyl acetate, n-Heptane, n-Hexane, N-Methylpyrrolidone, n-Pentane, N,N-Dimethylacetamide, N,N-Dimethylformamide, Pyridine, tert-Butanol, Tetrahydrofuran, Toluene, Triethylamine.
Immiscible with: Water — these form two layers.
Check any specific pair on the interactive miscibility chart.
Using Benzene in HPLC/GC
Aromatic nonpolar solvent; historically a normal-phase (adsorption) HPLC mobile-phase component and a GC sample/diluent solvent, and the apex reference for Snyder selectivity group VII in the solvent-selectivity triangle. Its high UV cutoff (~280 nm) makes it unsuitable for UV detection. Now almost entirely avoided/banned in analytical labs and pharma processes because it is a Class 1 (avoid) residual solvent and a confirmed human carcinogen; usually replaced by toluene where an aromatic solvent is needed.
Its Snyder polarity index is 2.7 (selectivity group VII), and its UV cutoff of 280 nm limits low-wavelength UV detection.See what the polarity index means and the full UV cutoff table.
Sources
- University of Toronto (TRACES) — Burdick & Jackson — Solvent UV cutoff table (absorbance = 1 AU, 1 cm cell)
- Stenutz / L. R. Snyder — Solvent polarity index (P′) and selectivity groups
- NIST — Chemistry WebBook — thermophysical properties (BP, density, refractive index)
- PubChem (NIH/NLM) — Compound property records (physical constants, CAS, formula)
- USP <467> / ICH Q3C — Residual Solvents — solvent classification (Class 1/2/3)
Values are compiled from public references and were last verified July 2026. See ourmethodologyfor how we source and verify. Always confirm critical values against primary references and the SDS.
Related solvents
Other selectivity group VII to compare with Benzene.