The production of synthetic fuels from alternative sources has increased in recent years as a cleaner, more sustainable source of transport fuel is now required. In response to European renewable energy targets, Ireland has committed, through the Biofuels Obligation Scheme of 2008, to producing 4% of transport fuels from biofuels by 2010 and 10% by 2020. In order to be suitable for sale in Europe, diesel fuels and biodiesels must meet certain European fuel specifications outlined in the EN 590: 2004 and EN 14214:2009 standards. The aim of this project is to prepare blends of varying proportions of synthetic diesel fuel (Cyn-diesel), produced from the pyrolysis of plastic, versus regular fossil diesel. The viscosity (mm(2)/s) and density (kg/m(3)) of these blends as well as of the regular diesel fuel were analysed in relation to compliance with the European fuel standard EN 590. (C) 2011 Elsevier Ltd. All rights reserved.