During pressure impregnation of wood products, excess creosote may be released from the treated materials. Leaching of spilled wastes from these application sites has been common. Creosote is also released to the environment from facilities through air emissions. Creosote-treated wood does not decay in the environment, and therefore its disposal is problematic. Creosote-treated wood should not be incinerated under uncontrolled conditions, as toxicants such as PAHs and halogenated dioxins and furans may be produced.