hydroxytoluene

Hydroxytoluene is a collective name for a family of chemical compounds consisting of a benzene ring bearing one hydroxyl group and one methyl group. The three positional isomers are 2-hydroxytoluene (o-cresol), 3-hydroxytoluene (m-cresol), and 4-hydroxytoluene (p-cresol). As a group, they are commonly referred to as cresols. Each isomer has the formula C7H8O and behaves as a phenol, giving them limited water solubility and acidic character.

Occurrence and production

Cresols occur naturally in coal tar and are produced industrially from coal tar fractions and as byproducts of refining processes. They can also be produced synthetically through methods that introduce a methyl group onto a phenol ring. Separation of the three isomers is typically achieved by fractional distillation and other purification steps.

Properties

Cresols are colorless to pale yellow liquids or solids with a distinctive phenolic odor. They are moderately soluble in organic solvents and only sparingly soluble in water. They act as weak acids (phenols) and can form phenoxide salts in basic media. Cresols are irritants and corrosive to skin and eyes and are hazardous to aquatic life.

Uses

Historically, cresols have been used as antiseptics and disinfectants and as components of wood preservatives (notably in creosote). They serve as chemical intermediates in the manufacture of dyes, fragrances, and various resins and plastics. Some cresol derivatives are used in herbicides and other industrial products.

Safety and regulation

Exposure can occur via inhalation, dermal contact, or ingestion. Due to irritant and toxic properties, handling requires appropriate protective equipment and ventilation. Environmental releases are subject to regulatory controls to mitigate health and ecological risks.