The quality of European diesel fuels is specified by the EN 590 standard. Even though these specifications are not mandatory, they are observed by all fuel suppliers in Europe. Beginning from the late 1990s, several diesel fuel properties - including cetane number, sulfur content and FAME biodiesel content - are also subject to environmental regulations.
While EN 590 is primarily focused on onroad applications, many European Member States specify the same fuel for use in nonroad mobile machinery but with the addition of a marker or dye for taxation purposes. Other member states have a separate standard for fuel for off-road mobile applications. An example of the later includes the UK that uses BS 2869 to define the specifications for fuel oils for a range of nonroad applications including nonroad mobile machinery.
Some of the important revisions of the EN 590 standard were:
- EN 590:1993 - The first EU diesel fuel specification. It established a sulfur limit of 0.2% and a cetane number of 49 in onroad and nonroad diesel fuels. Sometimes referred to as Euro 1 diesel fuel.
- EN 590:1996 - This standard reflected a new sulfur limit of 500 ppm. Cetane number remained at 49. Sometimes referred to as Euro 2 diesel fuel.
- EN 590:1999 - This standard reflected the sulfur (350 ppm) and cetane number (51) specifications by Directive 98/70/EC (so called Euro 3 diesel).
- EN 590:2004 - Sulfur limits of 50 ppm (so called Euro 4) and 10 ppm (Euro 5) as regulated by Directive 2003/17/EC. FAME content of 5%.
- EN 590:2009 - FAME content of 7% as regulated by Directive 2009/30/EC. This directive also adopts mandatory biofuel requirements for refiners and introduces a 10 ppm Sulfur limit in nonroad fuels effective 2011.
Regulatory Terms. In the EU regulatory language, “gas oil” is the term used to describe a wide class of fuels, including diesel fuels for onroad vehicles, fuels for nonroad vehicles, as well as other distillate fuels. Within the gas oil classification, fuels for onroad vehicles (typically with sulfur content below 0.05%) are referred to as “diesel fuels”, while fuels for nonroad mobile machinery (typically with sulfur content up to 0.2%) are referred to as “gas oils intended for use by non-road mobile machinery (including inland waterway vessels), agricultural and forestry tractors, and recreational craft”.
These terms are also linked to the terminology used in the EU Common Customs Tariff. Different goods are assigned unique CN (Combined Nomenclature) codes to identify the tariffs that apply. Diesel fuel for onroad applications has a CN code of 2710 19 41. Gas oils for nonroad mobile machinery can have a CN code of either 2710 19 41 or 2710 19 45 depending on sulfur level.