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Overview: Leaded Gasoline History and Current Situation
By Bill Kovarik
SUMMARY: Leaded gasoline should be counted among the great environmental disasters of the 20th century, given the numbers of people killed or slowly poisoned by the dull grey metal. Significantly. alternatives were well known from the beginning and preferred by the same researchers who created leaded gasoline. They originally saw it as nothing more than a bridge to other, safer fuels. Leaded gasoline was phased out in the US from 1975 - 1986 and in Europe in the 1990s. It is still being used in the developing world.
When you fill your car up at the gas pump, you may notice that you are using "unleaded" gasoline.
Lead is not something that comes with gasoline that has to be taken out -- it was deliberately added by the oil industry to boost "octane" or anti-knock ratings for fuel. It had to be phased out by government order, for public health reasons, starting in 1975, and concluding in 1986. It was also banned in various European nations in the 1990s. It is still having serious public health impacts in developing nations, and a complete global phase-out has long been advocated by the World Health Organization and all other international health organizations.
Most recently, the "Declaration of Dakar" of June 28, 2001, part of the World Bank's Clean Air Initiative, called for help in phasing out leaded gasoline in 25 sub-Saharan nations.
Chart showing drop in blood lead levels in close correlation to drop in lead content of gasoline. (EPA).
Leaded gasoline is typically a suspension of 3 to 4 cc tetra-ethyl lead per gallon of gasoline. Although diluted at over 1,000 to 1, the lead is readily absorbed into the skin on contact with gasoline or into the lungs from automotive exhaust.
Leaded gasoline was discovered on Dec. 9, 1921, at the General Motors research labs in Dayton Ohio. GM researchers had been testing fuel blends since 1916, trying to stop engine "knock." Knock was a problem that was preventing the development of higher efficiency, higher compression engines. The problem was early, non-uniform detonation of fuels in the engine cylinder.
GM researchers tried many different additives and found quite a few that worked well. Ethyl alcohol from cellulosic materials was for many years their strong preference. "Of course" Thomas A. Midgley of GM wrote in a memo to his boss, GM research vice president Charles Kettering, alcohol was "the fuel of the future." The great thing about alcohol was that it could be made from plants, and thus it would be available indefinitely after the oil ran out -- and that made Detroit happy. But the problem was that the oil industry would not sell pure alcohol as a fuel. So Detroit needed something to bridge the gap,
That something was the "pill" approach -- a few drops or grams of a substance that could be added to gasoline to stop the knock and allow Detroit to make high compression engines, which would be more efficient and more powerful and -- not incidentally -- easier to switch to alternative fuels if or when the time came for Detroit to leave the oil industry behind.
After a frantic search for results to justify further research, the company gave Midgley a litle extra time in 1921. He started working systematically through the periodic table of elements although he continued promoting alcohol fuel blends to meetings of the Society of Automotive Engineers. Tetraethyl tin had some effect, but a solution of tetraethyl lead stopped engine knock fairly well in a research engine on December 9, 1921. The solution was difficult to produce, explosive and quite poisonous, as GM researchers found in the winter of 1922. Even as late as the summer of 1922, Midgley and his assitant T.A. Boyd were championing alcohol fuel from vegetable sources.
GM started marketing its "Ethyl" fluid in 1923. In 1924 it joined with Standard Oil (Exxon) to form a partnership called the Ethyl Corp. Since DuPont was a one-third owner of GM at the time, the three major corporations all had a hand in the development and marketing of leaded gasoline. Other companies quickly joined in, including Andrew Mellon's Gulf Oil Co.with an exclusive contract for Southeastern U.S. distribution of leaded gasoline. Mellon was Secretary of Treasury during this time and in charge of the Public Health Service, which was investigating leaded gasoline.
The public controversy started when about five workers at a grossly unsafe Standard Oil refinery went violently insane in 1924. Many others were also hospitalized. Public health experts, including Alice Hamilton of Harvard and Yendell Henderson of Yale, vehemently opposed the use of lead in gasoline as a menace to public health. Henderson called it "the single most important question in the field of public health that has ever faced the American public."
In 1925 the Public Health Service convened a conference on leaded gasoline. The structure of the conference was slanted towards industry, which may have had something to do with the influence of Andrew Mellon. At the conference, Hamilton called GM vp Charles Kettering "nothing but a murderer" for distributing leaded gasoline. Lead poisoning, as Hamilton knew, had been a familiar and dreaded "occupational disease" throughout centuries of European history.
Hamilton also insisted that there were other ways to get an anti-knock (higher octane) fuel.
Kettering and others, speaking for GM and Standard Oil (which together jad created the Ethyl Corp. early in 1924) claimed that they did not know of alternatives "in the parrafin series" that gave anti-knock results. Frank Howard of Standard went much further, saying that civilization rested on engines and fuels, and that (in his immortal words) leaded gasoline had come "like a gift from heaven."
But even a quick glance at Chemical Abstracts would have shown the Public Health Service and the news media that GM had gone to the trouble of patenting many alternatives just in case leaded gasoline didn't work out. Clearly, the public watchdogs were fast asleep.
We now know from confidential GM documents that Kettering and others were very worried about competition from alternatives to leaded gasoline. They exchanged anxious memos about the competing anti-knock techniques. These included catalytic cracking, use of benzene and use of higher parrafin- derived alcohols (eg, tertiary butyl alcohol) being used by Sun, Arco and other oil companies at the time. Ethyl alcohol from farm products was also a serious competitive threat in Europe until the late 1930s.
These worries were one reason why production schedules were pushed to the limit and unsafe plant conditions were allowed to exist. The haste to beat the competition contributed to the 17 deaths from tetraethyl lead in the 1920s.
As an historian looking to the implications of these events, several items cause particular concern:
First, that it was so easy for industry to distort and nearly bury the history of this environmental disaster under layers of tertiary materials like company reports and public relations memos. Only a chance release of 80 linear feet of raw, unclassified GM files in 1992 provided any primary historical documents to researchers. There are still many thousands of documents held in private that have not been made public, contrary to the assertions by the DuPont and the Ethyl Corp. *
Secondly, if the government found it so difficult to remove one of history's best known poisons from an item of everyday commerce, how much harder will it be to re-examine and retool technology for the more difficult environmental challenges of the 21st century?
World Bank charts of lead poisoning, early 1990s, various cities around the world. Measureable effects are well documented at 10 mg/dl. All but the US are at least twice that level, with Bangkok at four times the level.
* See Heroic Myths and Tetraethyl Lead at this site.