General Motors researchers commercially introduced leaded gasoline.
Though ethanol was already in use as an anti-knock fuel additive, the GM scientists who discovered tetra ethyl lead (TEL), the ingredient in leaded gasoline, brought it to market in 1923. Public outcry soon followed when refinery workers exposed to TEL experienced severe health symptoms, including violent insanity and death. GM's insistence that TEL was only dangerous in concentrated form at the refinery (and not when diluted in gasoline) was met with public skepticism. Nevertheless, lead soon replaced ethanol as the prevalent anti-knock additive.