What types of wood preservatives are used to pressure treat wood crossties?
Virtually all hardwood crossties produced in North America today are pressure treated with creosote or creosote solutions. The US Environmental Protection Agency (EPA) has approved and registered creosote for this industrial application. Other standardized preservatives that can be used include Copper Naphthenate and Pentachlorophenol although Penta has not been used by railroads in decades. Some producers also use a dual treatment system where borate compounds are applied prior to a second treatment with creosote. The borates diffuse throughout the hard-to-treat heartwood of many species and provides additional protection for wood used in high decay areas.
Virtually all hardwood crossties produced in North America today are pressure treated with creosote or creosote solutions. The US Environmental Protection Agency (EPA) has approved and registered creosote for this industrial application. Other standardized preservatives that can be used include Copper Naphthenate and Pentachlorophenol although Penta has not been used by railroads in decades. Some producers also use a dual treatment system where borate compounds are applied prior to a second treatment with creosote. The borates diffuse throughout the hard-to-treat heartwood of many species and provides additional protection for wood used in high decay areas. Also, in January 2010, the AWPA approved the use of ACZA (Ammoniacal Copper Zinc Arsenate) as an accepted wood preservative for the protection of ties. For example, Douglas fir is a strong, plentiful species – well-suited for use as ties – but not readily treated with other preservatives. Tests of ACZA-treated ties have shown low co
