The document sets out best practice guidance for those using ULSD. The US government has federal regulations mandating ULSD use, and so the AEM decided to take the step of sending out educational outreach to help inform machine operators and others on the farm or construction jobsites about ULSD characteristics that can affect safety during refuelling.

The association said that the bulletin explains that the removal of sulphur and other compounds in ULSD fuel decreases its conductivity and increases its ability to store static charge. "Static electricity discharge when combustible vapours are present could result in a fire or explosion," was one quote the organisation sought to highlight.

AEM was also keen to emphasise that all off-highway diesel-powered machinery, including older legacy or vintage agricultural and construction vehicles, have been using this new formulation of ULSD and while it may not be noticeable to most users, there may be a greater risk of static electricity ignition if their refuelling systems are not properly functioning or maintained.

The bulletin urges industry workers to contact their fuel or fuel system supplier to ensure the delivery system is in compliance with fueling standards for proper grounding and bonding practices.

Mike Weber, AEM technical and safety services manager, said: "About 90% of off-road equipment is run on diesel and at one time the fuel had upwards of 5000ppm sulphur content compared with 15ppm today. 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 refuelling."