This book discusses the history of leaded gasoline in Swizerland while taking into account the political, legal, economic and ecological points of view. Since the turn of the millennium, leaded gasoline has been banned in Western Europe. Its elimination is recognised as one of the greatest success stories of environmental protection. However, the antiknock additive tetraethyl lead was already prohibited in most industrialised countries in the 1920s due to serious concerns about its health impact. But under the pressure of the automotive and fuel industries, the ban was soon repealed. Subsequently, the arguments for the revocation of the ban, as presented by the industry and public authorities, have been found to be largely misleading. The consequences of a chemical's use, when the long-term impacts are not considered, can be great. A cost and benefit analysis in the 1980s revealed that the costs of leaded gasoline exceeded the benefits several fold. The case study demonstrates that the path to the ban on leaded gasoline was not a clear-cut success. Unfortunately, the story seems to be repeating itself with the antiknock additive MTBE. Lessons of history are rarely used to reduce current and future risks.