Creosote Wood Treatment FAQs
Q&A: Creosote’s Use as a Wood Preservative
How long has creosote been used as a wood preservative?
Wood preservation has been an integral part of the world’s industrial modernization. Precursors to creosote have been used as early as the early 1700s. For example, in 1716, a patent was granted to England’s Dr. William Crook for a precursor to creosote, “One Part of which is the Oyle or Spirit of Tarr,” to protect ships’ wood planking from decay and worms.
Later on in the Industrial Revolution, the railroad industry was built, literally, on creosote-treated wood. For example, in 1865, a plant was built in Somerset, Massachusetts, to treat wood intended for railway use. A decade after this, the Louisville and Nashville Railroad built a plant in West Pascagoula, Mississippi, to treat wood for ties and other railway necessities.
A timeline and other information can be found on our History of Creosote page.
How is creosote-treated wood used in the railroad industry?
Creosote-treated wood crossties are an integral part of the railroad transportation network in North America. It is estimated that 20 million railroad crossties will be produced in 2020. Approximately 95% of railroad crossties are treated with creosote.
What are some of the benefits that the railroad industry sees in the use of creosote-treated wood?
Railroad crossties treated with creosote have many useful characteristics. They can be easily and safely installed; will withstand temperature changes, vibration, and compression; will resist drifting out of position; and do not require insulators (thereby allowing electric signal current to flow).
What other sectors use creosote-treated wood products?
Creosote-treated utility poles are an integral part of the telecommunications infrastructure in the United States. It should be noted that utility poles are subject to the harshest conditions in nature, including rain, snow, ice, wind, decay, and insects. Approximately 130 million utility poles are currently in service across the United States. In service today, these wood utility poles have been preservative treated; it is estimated over 40% of them have been creosote-treated.
Also consider that in other areas such as aquatic and wetland areas, creosote-treated wood is used in foundation and marine pilings, among other uses.
How is creosote wood preservative different from creosote in my chimney?
Creosote in a chimney develops from the burning of wood with the vapors condensing inside the chimney. Creosote wood preservative is a material produced from coal tar according to specific standards used in accordance with another set of standards to treat wood products such as railroad crossties.
What is the primary purpose of using creosote in wood products?
Without creosote treatment and preservation, the exterior service life of untreated wood is only about five years. Creosote protects wood from infestation and decay, greatly prolonging the useful life of wood products.
The service life of creosote-treated railroad crossties, for example, exceeds 50 years. The lifespan of creosote-treated bridges, piers, docks, boardwalks, decks, and buildings in aquatic and wetland areas ranges from 40 to 75 years. The useful life of creosote-treated utility poles exceeds 75 years.
Creosote is not normally viewed as an environmentally friendly material. Does it benefit the environment in any way?
Due to creosote’s ability to increase the service life of wood, which is the only structural engineered renewable resource, trees can be harvested much less frequently, contributing to conserving and extending the lifespan of timberlands. Railroad crossties that are treated with creosote can, at the end of their service life, be reused and recycled to industrial boilers as fuel.
How are Creosote-Treated Railroad Ties Recycled?
The majority of railroad ties in North America are treated with creosote to extend their useful life. What happens to crossties when they reach the end of their service? Most are recycled and reused. Learn more here.
Creosote and the Railroad Industry
Coal tar distillates in the form of creosote are a cost-efficient and integral part of North America’s transportation industry. Creosote was first used in the railroad industry in 1838 and still maintains approximately 98% of the North American crosstie market.
Railroad crossties distribute the load of railroad cars and maintain gage between the rails. Close to 1 billion crossties are currently in service.
Of the current track mileage in the United States, 200,000 miles are privately owned with an additional 20% owned by port authorities and the federal and state governments.
It is estimated that 24 million crossties were inserted into the railroad system in 2017 alone. Creosote-treated crossties represent 93% of that total.