creosote

Creosotes are a category of carbonaceous chemicals formed by the distillation of various tars, and by pyrolysis of plant-derived material, such as wood or fossil fuel. They are typically used as preservatives or antiseptics. Some creosote types were used historically as a treatment for components of seagoing and outdoor wood structures to prevent rot (e.g., railroad ties and bridgework, see image). Samples may be commonly found inside chimney flues where the wood or coal burns under variable conditions, producing soot and tarry smoke. Creosotes are the principal chemicals responsible for the stability, scent, and flavor which is characteristic of smoked meat; the name is derived from the Greek kréas (κρέας), meaning "meat", and sōtēr (σωτήρ), meaning "preserver".