Creosote

**Semantic type:** Organic Chemical

**Definition:** A class of carbonaceous chemicals formed by the distillation of various tars and pyrolysis of wood or fossil fuel. They are used industrially as antiseptics and preservatives. Large quantities of creosote can be toxic and exposure can cause a wide variety of issues from skin irritation to death depending on the route and level (concentration and duration) of exposure. Creosote buildup in domestic heating systems can cause chimney fires.