Standard Diesel

The specific European reference, which harmonises throughout Western Europe the national specifications for diesel fuel for transport purposes, is EN 590 issued by the CEN, which, in turn, is known in Italy as UNI EN 590. The characteristics of diesel fuels with an environmental impact have been defined at a European level in the EU Directive 2009/30/CE. This includes sulphur levels and, since 1 January 2009, all diesel fuels sold in the market have been sulphur-free.

In response to the EU Directives, the technical specifications for diesel fuels for transport purposes have evolved to include blends of biodiesel up to current levels of 7%v/v of this biofuel.
Diesel quality is determined also by seasonality, with certain characteristics differing between summer and winter.