Is reformulated gasoline more toxic than unleaded?
The evidence so far indicates that the components of reformulated gasolines ( RFGs ) are more benign than unleaded, and that the tailpipe emissions of hydrocarbons are significantly reduced for cars without catalysts, and slightly reduced for cars with catalysts and engine management systems. The emissions of toxic carbonyls such as formaldehyde, acetaldehyde and acrolein are increased slightly on all vehicles, and the emission of MTBE is increased about 10x on cars without catalysts and 4x on cars with catalysts [55]. When all the emissions ( evaporative and tailpipe ) are considered, RFGs significantly reduce emissions of hydrocarbons, however the emissions of carbonyls and MTBE may increase [55]. There has been an extensive series of reports on the emissions from RFGs, produced by the Auto/Oil Air Quality Improvement Research Program, who measured and calculated the likely effects of RFG [18,19,20,58,59,60,61]. More research is required before a definitive answer on toxicity is avai
