Exhaust Gas Emissions and Mutagenic Effects of Diesel Fuel, Biodiesel and Biodiesel Blends

The replacement of petrol derived fuels by biogenic fuels from renewable resources has become of worldwide interest and is scientifically investigated for its environmental costs and benefits. Biodiesel has been proven as a suitable alternative to fossil diesel fuel and blends up to 20% biodiesel with common diesel fuel are a strongly pushed policy in the U.S.A. and the EU.

To investigate the influence of blends on the emissions and possible health effects, we performed a series of studies with several engines (Euro 0, III and IV) measuring regulated and non-regulated exhaust compounds and determining their mutagenic effects using the Bacterial Reverse Mutation Assay (Ames-Test) according to OECD Guideline 471.

Emissions of blends showed an approximate linear dependence on the blend composition, in particular when regulated emissions are considered. However, a negative effect of blends was observed with respect to mutagenicity of the exhaust gas emissions. In detail, an increase of the mutagenic potency was found in the blends showing the maximum using B20. From this point of view, B20 must be considered as a critical blend, in case diesel fuel and biodiesel are used as binary mixtures. Further investigations are initiated to clarify the toxic mechanisms of these results.