Cresols (also
hydroxytoluene) are
organic compounds which are
methylphenols. They are a widely occurring natural and manufactured group of
aromatic organic compounds, which are categorized as
phenols (sometimes called
phenolics). Depending on the
temperature, cresols can be
solid or
liquid because they have
melting points not far from room temperature. Like other types of phenols, they are slowly
oxidized by long exposure to
air and the impurities often give cresols a yellowish to brownish red tint. Cresols have an
odor characteristic to that of other simple phenols, reminiscent to some of a "
coal tar" smell. The name cresol reflects their structure, being phenols, and their traditional source,
creosote.