Fatty alcohols (or long-chain
alcohols) are usually high-molecular-weight, straight-chain
primary alcohols, but can also range from as few as 4-6 carbons to as many as 22-26, derived from natural fats and oils. The precise chain length varies with the source. Some commercially important fatty alcohols are
lauryl,
stearyl, and
oleyl alcohols. They are colourless oily liquids (for smaller carbon numbers) or waxy solids, although impure samples may appear yellow. Fatty alcohols usually have an even number of carbon atoms and a single
alcohol group (-OH) attached to the terminal carbon. Some are unsaturated and some are branched. They are widely used in industry. As with fatty acids, they are often referred to generically by the number of carbon atoms in the molecule, such as "a C12 alcohol", that is an alcohol having 12 carbons, for example
dodecanol.