Methanol alcohol molecule. Molecular model of methanol, the simplest alcohol with just one carbon atom (grey). It is a flammable, light, colourless liquid, which is poisonous and causes blindness if ingested. Its main uses are as an organic solvent (a liquid that dissolves many other substances resulting in a solution), as a fuel and as a component in the chemical formulation of biodiesel fuel. Atoms are colour-coded: hydrogen (white), oxygen (red) and carbon (grey).