Solvent

Pressed from the seed of Ricinus communis, castor oil is the one common vegetable oil that will dissolve the staining dyes used in lipstick, which is how it became the liquid backbone of the bullet.

A volatile silicone ring of five repeating units, used as a carrier that spreads a product evenly and then evaporates, and now restricted in European cosmetics on environmental rather than dermatological grounds.

A small three-carbon alcohol with a hydroxyl group on every carbon, isolated from olive oil in 1779 and now the most widely used humectant in cosmetics.

A branched twelve-carbon hydrocarbon that works as a volatile solvent: it thins a formulation during application and then evaporates completely, leaving the pigment and the film former behind.

A synthetic aromatic alcohol that has become the default broad-spectrum preservative in cosmetics, permitted in the European Union at a maximum of one per cent.

The fully hydrogenated form of squalene, a hydrocarbon the human body makes on its way to cholesterol and secretes in sebum; saturating it removes the six double bonds that let the parent go rancid.