Understand the Static Electricity Risks when Refueling with Ultra Low Sulfur Diesel

Tier 4 engine regulations require the use of ULSD.The removal of sulfur and other compounds in Ultra Low Sulfur Diesel (ULSD) decreases its conductivity and increases its ability to store static charge, according to a new Association of Equipment Manufacturers’s (AEM’s) bulletin called “ULSD…Not Your Same Old Diesel Fuel Anymore.” The bulletin warns of the greater static electricity ignition hazards associated with the use of ULSD. With federal regulations mandating ULSD use, AEM undertook the educational outreach to help inform machine operators and others on the farm or construction jobsites about ULSD characteristics that can affect safety during refueling.

“Static electricity discharge when combustible vapors are present could result in a fire or explosion,” the bulletin notes.

All off-highway, diesel-powered machinery (including older legacy or vintage agricultural and construction vehicles) have been using this new formulation of ULSD. While it may not be noticeable to most users, there may be a greater risk of static electricity ignition if their refueling systems are not properly functioning or maintained.

The bulletin urges industry workers to consult with their fuel or fuel system supplier to ensure the delivery system is in compliance with fueling standards for proper grounding and bonding practices. A multi-sector AEM ad hoc committee of member companies developed the best practices bulletin. Initial resource supporters are the Agricultural Retailers Association, Agrievolution Alliance, American Rental Association, Truck  and Engine Manufacturers Association and the North American Equipment Dealers Association. AEM is encouraging industry groups and government entities to disseminate the bulletin to foster widespread understanding of the related risks during ULSD refueling.

“About 90 percent of off-road equipment is run on diesel and at one time the fuel had upwards of 5,000-ppm sulfur content compared with 15 ppm today,” stated Mike Weber, AEM technical and safety services manager. “ULSD is now required for on-highway and off-highway applications in the North American market, and we need to educate users who may be unaware of the changes in the physical properties of ULSD and the potential for harm during refueling.”

For more information, download the bulletin from the AEM website (www.aem.org) in the Safety, Regulatory and Technical section.