cresylic acid

Cresylic acid is a chemical compound that refers to a crude mixture of cresols, which are methylphenols. It can also describe a mixture of phenols, including cresols and xylenols, derived from coal tar or cracked petroleum oils.1

Cresols themselves exist in three structural forms: ortho-, meta-, and para-cresol. These are typically obtained as a mixture, also known as tricresol or cresylic acid. All forms of cresol are highly toxic and can be absorbed through the skin in fatal amounts.2

Despite their toxicity, cresols are effective disinfectants and antiseptics in low concentrations. They are also used in sheep-dips and are key components of creosote, a wood preservative. Cresols can be used in the production of phenol-formaldehyde resins, and specific isomers have further applications, such as in photographic developers or as antioxidants. Salts of cresol or cresylic acid are known as cresylates and are used commercially. Cresylic acid is distinct from cresotic acid, which refers to isomeric acids derived from cresols.234