Salicylic Acid, a white, crystalline solid that is a strong organic acid. It occurs in small amounts in the roots, leaves, flowers, and fruits of many plants. Salicylic acid is used in the manufacture of dyes and as a preservative for hides and glues. Because it has antiseptic properties, it is used in ointments for treating skin diseases such as eczema and ringworm. It is also used for removing calluses and warts. Commercial salicylic acid is made from phenol by chemical processes.

Salicylic acid combines with metals and organic compounds to form derivatives called salicylates, many of which are drugs. The commercially important salicylates are acetylsalicylic acid (aspirin), methyl salicylate (chief component of oil of wintergreen), and phenyl salicylate (salol). Used in moderation, salicylate drugs are relatively safe. Large doses, however, are poisonous and can cause severe acidosis.

Chemical formula: HOC6H4CO2H.