1-Propanol

Ball-and-stick Stick Space-filling

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12 atoms, 11 single bonds.

IUPAC name: propan-1-ol
Molar mass: 60.0960(86) g/mol
Atoms: 12
SMILES: CCCO
InChIKey: BDERNNFJNOPAEC-UHFFFAOYSA-N
PubChem CID: 1031

Made of

Structural formula of 1-propanol. Each unlabelled corner is a carbon atom, and the four hydrogens on carbon are not drawn. It shows which atoms are joined to which, not the shape. The model above shows the shape.

ChEBI, the Chemical Entities of Biological Interest database, files 1-propanol as a short-chain alcohol: propane with a hydroxy group, –OH, in place of one hydrogen on an end carbon. Its name from IUPAC, the International Union of Pure and Applied Chemistry, is propan-1-ol. The prefix prop- in that name marks a chain of three carbon atoms, Chem1 explains. The formula is C₃H₇OH and the molar mass 60.1 g/mol. The hydroxyl group is the defining mark of the alcohols, a word that entered chemical nomenclature as the name of the class in 1852, on Chem1’s account.

CAMEO Chemicals, a US emergency-response database, describes a clear, colourless liquid whose sharp, musty smell recalls rubbing alcohol, which is its isomer isopropyl alcohol. NIOSH, the US occupational safety institute, calls the odour mild. With water it is miscible, mixing in any proportion, according to the International Chemical Safety Cards (ICSC).

Structure and bonding

1-Propanol’s twelve atoms are built on a C–C–C–O chain. The O sits at one end, bonded to an end carbon and carrying a single H of its own, while the three carbons share the other seven hydrogens. Isopropyl alcohol has the same C₃H₈O, but its O hangs from the middle carbon. Chem1 notes that a group able to occupy more than one position on a chain gives rise to isomers, and these two alcohols are that pair. In Space-filling, the oxygen and its hydrogen cap one end of a short, lumpy rod.

In PubChem’s computed pose, the angles measure 111.8° for C–C–C, 108.9° for C–C–O and 107.6° for C–O–H, values of the model rather than of an experiment. All three sit close to the 109.5° that Chem1 gives between any two bonds of methane. The three carbons and the oxygen lie in one plane, a zigzag rather than a straight line. The zigzag is only one arrangement: carbon–carbon single bonds can rotate, Chem1 notes, so the chain also takes other shapes.

Every one of the eleven bonds is single, with no ring, charge or alternative resonance form, and the drawing is the molecule’s real bonding.

Where it turns up

Distilleries are one source. When wine is distilled, 1-propanol can be isolated from the head fractions, the first portions to come over, according to the Hazardous Substances Data Bank (HSDB). When spirits are rectified, or distilled again, it turns up in the tail fractions, the last to come over. Living things carry it as well: the LOTUS natural-products database reports it in Tuber melanosporum and Zea mays, among other organisms.

Food carries it too. The US Food and Drug Administration (FDA) allows it in food as a synthetic flavouring, HSDB records, and its flavour is characteristically ripe and fruity. Car-care and personal-care products are among the household goods that contain it, according to the Consumer Product Information Database. HSDB lists it as a solvent for natural gums and polishes, and as an ingredient of dental lotions.

Why it matters

In the oxo process, ethylene is first converted to propanal, an aldehyde, which is then hydrogenated, or combined with hydrogen, to give 1-propanol, HSDB says. Sasol’s Fischer–Tropsch process, which begins by gasifying coal, gives it as one product. It also arises as a by-product of methanol synthesis and of oxidising propane and butane. The aggregated US volume for 2023 was 550 million to just under 700 million pounds, according to reports to the Environmental Protection Agency (EPA).

In HSDB’s 1980 breakdown, chemical manufacture took most of it: 37 per cent for n-propylamines, 18 per cent for n-propyl acetate and 19 per cent for other chemicals. Solvent use took 23 per cent and cattle feed 3 per cent. As a specialty solvent it goes into printing inks for polyolefin and polyamide plastic film. The FDA permits it in cattle feed as a source of metabolisable energy. The World Health Organization’s drug classification lists propanol among antiseptics and disinfectants under code D08AX03.

Properties

Properties of 1-propanol Molar mass summed from IUPAC/CIAAW 2024 standard atomic weights; formula, atom and bond counts and PubChem's molecular weight from PubChem CID 1031.
Property	Value	Unit	Source
Molecular formula (Hill order)	C₃H₈O
Molar mass	60.0960(86) g/mol	g/mol	IUPAC/CIAAW 2024
Carbon atoms	3
Hydrogen atoms	8
Oxygen atoms	1
Bonds	11
PubChem molecular weight	60.1 g/mol	g/mol	PubChem

Safety

1-Propanol is a highly flammable liquid, and its harmonised EU classification adds serious eye damage and drowsiness or dizziness under the signal word Danger. The ICSC warns that it removes fat from the skin, which can leave it dry or cracked, and that swallowed liquid can easily enter the airways. Workplace exposure limits exist; the NIOSH card and the PubChem Laboratory Chemical Safety Summary hold them with the rest of the hazard data.

Questions

Is 1-propanol the same as isopropyl alcohol?

No. Both have the formula C₃H₈O, but they are separate compounds, and their systematic names differ by one digit: propan-1-ol and propan-2-ol. The NIOSH card for 1-propanol gives n-propanol, propyl alcohol and ethyl carbinol as its other names. Rubbing alcohol, 2-propanol and sec-propyl alcohol belong to the isomer, according to the NIOSH card for isopropyl alcohol.

Does 1-propanol mix with water?

Yes. It is miscible with water, meaning the two mix in any proportion, according to the International Chemical Safety Cards. The Hazardous Substances Data Bank (HSDB) records that it is also miscible with propylene glycol, and that it dissolves in acetone, benzene and ether.

How does the body break down 1-propanol?

It is absorbed through the gut and the lungs, and NIOSH lists skin absorption among its exposure routes; HSDB reports that it is absorbed more readily than ethanol. The enzyme alcohol dehydrogenase metabolises it, and the body readily oxidises it to propionic acid, then on to carbon dioxide and water. In rat liver, enzymes also oxidise it to its aldehyde, propanal.

Does 1-propanol cause cancer?

The American Conference of Governmental Industrial Hygienists (ACGIH) places it in group A4, not classifiable as a human carcinogen. A different hazard appears in the revised classification of NITE, a Japanese government body: suspected of harming fertility or an unborn child. The US Environmental Protection Agency's Safer Choice programme marks it with a green half-circle, its rating for a chemical expected to be of low concern.

Made of the same elements

C₃H₈O Isopropyl alcohol 12 atoms, 11 single bonds.
C₄H₈O Butanone 13 atoms, 12 bonds.
C₃H₈O₂ Propylene glycol 13 atoms, 12 single bonds.
C₃H₆O Acetone 10 atoms, 9 bonds.
C₃H₇COOH Butyric acid 14 atoms, 13 bonds.
CH₃COOC₂H₅ Ethyl acetate 14 atoms, 13 bonds.
C₃H₈O₃ Glycerol 14 atoms, 13 single bonds.
C₄H₉OH 1-Butanol 15 atoms, 14 single bonds.

All 51 compounds made of carbon, hydrogen and oxygen

C₂H₅OC₂H₅ Diethyl ether 15 atoms, 14 single bonds.
CH₃OCH₃ Dimethyl ether 9 atoms, 8 single bonds.
C₂H₅OH Ethanol 9 atoms, 8 single bonds.
C₂H₅COOH Propionic acid 11 atoms, 10 bonds.
C₂H₆O₂ Ethylene glycol 10 atoms, 9 single bonds.
C₃H₆O₃ Lactic acid 12 atoms, 11 bonds.
CH₃CHO Acetaldehyde 7 atoms, 6 bonds.
C₂H₄O Ethylene oxide 7 atoms, 7 single bonds.
C₆H₅OH Phenol 13 atoms, 13 bonds.
CH₃COOH Acetic acid 8 atoms, 7 bonds.
C₆H₅CHO Benzaldehyde 14 atoms, 14 bonds.
CH₃OH Methanol 6 atoms, 5 single bonds.
C₆H₅COOH Benzoic acid 15 atoms, 15 bonds.
C₂H₄O₃ Glycolic acid 9 atoms, 8 bonds.
C₄H₆O₅ Malic acid 15 atoms, 14 bonds.
C₈H₈O₃ Methyl salicylate 19 atoms, 19 bonds.
C₈H₈O₃ Vanillin 19 atoms, 19 bonds.
C₆H₈O₆ Ascorbic acid 20 atoms, 20 bonds.
CH₂O Formaldehyde 4 atoms, 3 bonds.
C₇H₆O₃ Salicylic acid 16 atoms, 16 bonds.
C₄H₆O₆ Tartaric acid 16 atoms, 15 bonds.
C₉H₈O₄ Aspirin 21 atoms, 21 bonds.
C₆H₈O₇ Citric acid 21 atoms, 20 bonds.
HCOOH Formic acid 5 atoms, 4 bonds.
H₂CO₃ Carbonic acid 6 atoms, 5 bonds.
H₂C₂O₄ Oxalic acid 8 atoms, 7 bonds.
C₆H₁₂O₆ Fructose 24 atoms, 24 single bonds.
C₆H₁₂O₆ Glucose 24 atoms, 24 single bonds.
C₁₀H₂₀O Menthol 31 atoms, 31 single bonds.
C₁₄H₁₄O₃ Naproxen 31 atoms, 32 bonds.
C₁₅H₁₆O₂ Bisphenol A 33 atoms, 34 bonds.
C₁₃H₁₈O₂ Ibuprofen 33 atoms, 33 bonds.
C₂₀H₁₄O₄ Phenolphthalein 38 atoms, 41 bonds.
C₁₈H₂₄O₂ Estradiol 44 atoms, 47 bonds.
C₁₂H₂₂O₁₁ Lactose 45 atoms, 46 single bonds.
C₁₂H₂₂O₁₁ Sucrose 45 atoms, 46 single bonds.
C₁₉H₂₈O₂ Testosterone 49 atoms, 52 bonds.
C₁₆H₃₂O₂ Palmitic acid 50 atoms, 49 bonds.
C₂₁H₃₀O₂ Progesterone 53 atoms, 56 bonds.
C₁₈H₃₄O₂ Oleic acid 54 atoms, 53 bonds.
C₂₁H₃₀O₅ Cortisol 56 atoms, 59 bonds.
C₂₇H₄₄O Cholecalciferol 72 atoms, 74 bonds.
C₂₇H₄₆O Cholesterol 74 atoms, 77 bonds.