Creosote is a dark, oily liquid derived from the distillation of tar, primarily from wood or coal. It has been used for centuries as a preservative for wood products, helping to protect them from decay, insects, and other environmental damage. In addition to its use in preserving wood, creosote is also found in some medicinal applications, although its use has declined due to safety concerns. Prolonged exposure to creosote can be harmful, leading to skin irritation and other health issues. As a result, its use is regulated in many countries.