Creosote! What’s that?
Creosote is the black goo that railroad ties are treated with. You may have noticed the same stuff on the bottom of utility poles, and in fact it is one of the most common wood preservatives used in the United States. Creosote is made from a wide range of chemicals and is divided into two types. The first type is wood creosote which is created through the heating of beechwood or creosote bush. However, this form is not widely used in the United States and will be excluded from this discussion. The more common type of creosote is created when coal is heated to produce coke (a cleaner burning form of coal) or natural gas. This process produces coal tar creosote, coal tar, and coal tar pitch, which are all mixtures of similar compounds and are referred to here simply as creosote.
