By David Webb and Larry Ebner
Key Changes for Worker Safety and Treatment Processes
The U.S. Environmental Protection Agency (EPA) recently approved the continued use of creosote as a pressure-treatment wood preservative, granting approval under its rigorous Registration Review Program.
For more than 75 years, creosote has been a trusted and continuously registered wood preservative under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). While creosote itself is regulated as a pesticide by EPA, treated wood products are exempt from FIFRA regulation under the agency’s “treated articles exemption,” highlighting creosote’s longstanding role in infrastructure and industrial applications.
The Creosote Council
This continued approval was made possible through the diligent efforts of the Creosote Council, a national, joint data development and product stewardship group representing four U.S. creosote registrants. Since its founding in 1984, the Council has invested over $25 million in research adhering to good laboratory practices, ensuring creosote meets regulatory requirements while supporting ongoing research and stewardship initiatives.
The Creosote Council is composed of four U.S. creosote registrants: Arbor Preservative Systems LLC, Coopers Creek Chemical Corporation, Rain Carbon Inc., and Lonestar Specialties.
Revised Labeling Requirements
In conjunction with its continued registration, EPA, with the input and cooperation of the Council, has approved revised creosote product labeling. The revised labeling must be in place by March 31, 2025.
Reading and following a pesticide’s labeling are a very important part of using the pesticide properly. It is frequently said that “The Label is the Law.” The revised labeling must be read, understood, and followed precisely.
The following summary highlights the primary changes on the revised labeling but is not a substitute for reading and following the labeling itself.
Changes in Equipment Requirements
Revised equipment guidelines focus on minimizing exposure to creosote.
Control rooms must be isolated from cylinders and drip pad areas. If a facility’s control room is located less than 50 feet from either a cylinder door or a treatment system exhaust pipe, conformance to one of the following two conditions must be attained:
- The air to the control room must be supplied from an external source located more than 50 feet from the cylinder door or treatment system exhaust pipe.
- The air to the control room must be filtered to reduce organic contaminants using air filtration system technology to remove organic vapors from the air entering the control room. These systems must be maintained in accordance with their design specifications.
Changes in Treatment Process Requirements
To comply with updated safety and environmental standards, several key changes have been made to the treatment process requirements for creosote pressure treatment.
Cylinders must be ventilated by purging the post-treatment cylinder through a fresh air exchange. Per label revisions, the ventilation process will now require a minimum of three (3 each) volume exchanges. This exchange volume is based on an empty-cylinder volume.
This process may be accomplished by activating an air purge system that operates while the cylinder door remains closed or using an automatic device to open and hold the cylinder door no more than six inches to allow adequate ventilation when activating the vacuum pump.
If the second method is utilized at the conclusion of treatment, no personnel without the proper PPE may be located within 50 feet of the cracked cylinder door until the cylinder has been ventilated.
The exhaust pipe of the vacuum system or any air moving device utilized in conducting the air purge must terminate into a containment vessel such as a treating solution work tank or water effluent tank.
In addition, current requirements now specify that when pressure treating with creosote, automatic and remotely operated devices must be used to open, close, lock, and unlock cylinder doors. Also, the revised label language requires automatic methods must now be used to place and remove bridge rails as well.
For more than 75 years, creosote has been a trusted and continuously registered wood preservative under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and has had a longstanding role in infrastructure and industrial applications.
Changes in Personal Protective Equipment (PPE)
To enhance worker safety during creosote treatment processes, updated guidelines for personal protective equipment (PPE) have been introduced.
After completion of a minimum three volume exchange to ventilate cylinders, anyone within 50 feet of an open door or a pulled charge must use an OV/P100 respirator within the first 60 minutes.
All personnel conducting maintenance or repairs on any part of a treatment cylinder or on any emission point such as a valve or flange within the treating process must now wear the following PPE:
- A NIOSH-approved, properly fitting elastomeric full-mask respirator (PF50) with organic vapor (OV) cartridges or combination R or P filters,
- A NIOSH-approved gas mask with OV canister, and
- A NIOSH-approved powered air
purifying respirator with OV cartridges and combination HE filters
These same PPE requirements also apply to personnel who are within 50 feet of open cylinder doors prior to the required ventilation due to an equipment malfunction.
The revised labels will continue to include other longstanding requirements related to safety exposures, the treatment process, and treater certifications.
User Safety Requirements
To ensure the safety and well-being of employees, the following updates to user safety requirements have been implemented:
- Work clothing, PPE, work footwear, aprons, tools, or other items contaminated with creosote must remain at the facility. PPE must be cleaned and maintained. PPE should be stored and washed separately from other laundry. Clothing or PPE that is heavily contaminated cannot be reused.
- Eating, drinking, and smoking are prohibited in treating departments including cylinder load out areas, drip pads, and treating buildings.
- These may be allowed in control rooms provided they are physically isolated from potential sources of creosote contamination and if they are maintained in a clean condition.
- As a precaution, be sure to wash hands thoroughly before eating, drinking, chewing gum, using tobacco, or using the restroom.
Changes to the Treatment Process
To enhance the efficiency and environmental safety of the treatment process, the following procedural changes have been implemented:
- Final vacuums must be used to remove excess preservatives from treated wood products. They must be equal to or greater than initial vacuums and must be held for an appropriate period to remove excess preservative.
- For treated wood that will be used in marine or other sensitive aquatic environments, a double vacuum must be used.
- Following the pressure period and once the creosote has been pumped back to the work tank, a vacuum shall be applied for a minimum of one hour at not less than 22 inches of mercury or 560 kilo pascals adjusted for elevation of vacuum to recover excess preservative.
- Following the “breaking” of the vacuum and returning the cylinder to atmospheric pressure, a second vacuum must be applied for a minimum of three hours at the same intensity.
This article originally appeared in the January/February 2025 issue of the Railway Tie Association’s Crossties Magazine.