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.