Exhaust emissions and mutagenic effects of diesel fuel, biodiesel and biodiesel blends

The replacement of petroleum-derived fuels by renewable biogenic fuels has become of worldwide interest with the environmental effects being scientifically investigated. Biodiesel has been proven to be a suitable alternative to petrodiesel and blending up to 20% biodiesel with petrodiesel is policy promoted in the USA and the EU. To investigate the influence of blends on the exhaust emissions and possible health effects, we performed a series of studies with several engines (Euro 0, III and IV) using blends of rapeseed-derived biodiesel and petrodiesel. Regulated and non-regulated exhaust compounds were measured and their mutagenic effects were determined using the Bacterial Reverse Mutation Assay (Ames-Test) according to OECD Guideline 471. Exhaust emissions of blends were approximately linearly dependent on the blend composition, particularly when considering regulated emissions. However, a negative effect of blends was observed with respect to mutagenicity of the exhaust emissions. In detail, an increase of the mutagenic potential was found for blends with the maximum observed for B20. From this point of view, B20 must be considered as a critical blend when petrodiesel and biodiesel are used as binary mixtures.