1-Propanol
Properties
| State | Liquid at room temperature |
| Color | Colorless |
| Solubility | Miscible with water |
| Melting Point | -126 °C |
| Boiling Point | 97.1 °C |
About 1-Propanol
1-Propanol is the straight-chain three-carbon primary alcohol that sits between ethanol and 1-butanol on every alcohol table — molar mass 60.095 g/mol, boiling point 97.1 °C, miscible with water in all proportions because the OH group still dominates the three-carbon skeleton. It's the alcohol most chemistry students confuse with its much more famous isomer 2-propanol (isopropanol, the rubbing alcohol on the pharmacy shelf). The two share a molecular formula but diverge sharply in chemistry: 1-propanol oxidizes to propanal and then to propanoic acid, while 2-propanol oxidizes to acetone and stops there because the secondary carbon has no extra hydrogen to lose. Industrially, 1-propanol is produced by hydroformylation of ethylene to propanal followed by hydrogenation — the so-called oxo process — and the global market sits around 250,000 tonnes annually, dwarfed by the 2-propanol market by roughly a factor of ten. The 0.94-second flame-spread rate and the slightly higher boiling point make 1-propanol the preferred carrier solvent for flexographic printing inks where ethanol evaporates too fast and butanol too slowly.
Where you'll encounter it
If you've ever worked the lab bench in pharmaceutical formulation, 1-propanol is the recrystallization solvent you reach for when ethanol gives oils and methanol is too aggressive — its dielectric constant of 20 and slightly higher boiling point hit a sweet spot for crystallizing mid-polarity APIs. In a flexographic printing plant, the ink solvent vented from the press hood is mostly 1-propanol because it dries fast enough to keep the press running at 400 m/min but slowly enough not to skin over on the anilox roll between impressions. The HPLC chemists use it as a mobile-phase modifier when acetonitrile and methanol both fail to give baseline separation of closely eluting peaks — its higher viscosity raises backpressure but the selectivity shift can save a separation. And in the cosmetics industry, 1-propanol shows up in alcohol-based hairsprays where the slower evaporation than ethanol gives more time for the polymer film to set evenly across the hair shaft.
Common Uses
- Flexographic and gravure printing ink solvent at 30-60% by mass formulations
- Pharmaceutical recrystallization solvent for mid-polarity active ingredients
- HPLC mobile-phase modifier for selectivity tuning when methanol and acetonitrile fail
- Hairspray and cosmetic carrier solvent giving slower film-set than ethanol
- Hydroformylation feedstock for propyl acetate production via Fischer esterification
- Industrial degreaser for electronics assembly where IPA leaves residue rings
Safety Information
GHS classification: Flammable liquid Category 2 (H225, flash point 22 °C closed cup), Eye damage Category 1 (H318), Specific target organ toxicity single exposure Category 3 — narcotic effects (H336). OSHA PEL is 200 ppm 8-hour TWA; ACGIH TLV is 100 ppm TWA with 150 ppm STEL. About twice as toxic as ethanol on an oral LD50 basis (1870 mg/kg in rats vs. 7060 for ethanol) but markedly less toxic than methanol. The narcotic effect at high vapor concentrations means closed handling and adequate exhaust in print shops. Vapor density 2.07 — heavier than air, pools in pits and trenches. Forms explosive mixtures with air at 2.2-13.7 vol%.
This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals.