Volatile is the property of a substance to pass from a liquid or solid state to a gaseous state (evaporate) under certain conditions, most often at room temperature. It depends on the molecular weight, boiling point, intermolecular bonds and structure of the substance. The easier and faster the substance evaporates, the higher its volatility.

In pharmacy, perfumery and aromatherapy, volatility is of practical importance. For example, essential oils have varying degrees of volatility: the most volatile components evaporate first and create the initial fragrance note, while the less volatile ones stay longer. In chemistry, volatility is taken into account when storing substances: more volatile substances need sealed containers, because they evaporate easily and can be toxic or flammable.

Volatility also affects the pharmacokinetics of drugs, especially inhaled drugs. The higher the volatility, the faster the active ingredient enters the body through the respiratory tract. At the same time, this property can pose safety risks, especially when working with volatile toxic or irritating substances that quickly penetrate the air.