Why Is Lead In Gasoline?

However, even a minor reduction in average IQ on a population level, according to Sung Kyun Park, an associate professor of epidemiology and environmental health sciences at the University of Michigan School of Public Health, could have significant effects. He emphasized that the entire bell curve moves, with more people falling into what was once the extreme low end of IQ tests.

Until alternative, safer compounds replaced lead in gasoline, it was used to make engines run more smoothly. It has also been linked to heart and kidney disorders, in addition to having a lower IQ.

What was the reason for the removal of lead from gasoline?

Leaded gasoline was phased out in the United States in 1975, not for health concerns, but because it fouled catalytic converters, which were being legislated at the time to cut emissions. Leaded gas was legal to sell in the United States until January 1996, however it was relatively rare at the time and only used in historic cars and boats.

When did it become illegal to add lead in gasoline?

When health concerns about lead became apparent in the 1970s, unleaded gasoline was introduced. Leaded gasoline for use in on-road cars was totally phased out in the United States on January 1, 1996. Leaded gasoline is no longer used in most other countries’ cars. Gasoline is now commonly sold in three grades at retail stores.

What are the consequences of gasoline containing lead?

The United Nations announced on Monday an important environmental and public health milestone: the worldwide phase-out of leaded gasoline in automobiles and road vehicles.

Algeria was the last holdout, with substantial inventories of leaded gasoline; those stockpiles ran out in July, and Algeria has now switched to unleaded gasoline.

Lead poisoning has serious societal consequences, including brain damage, chronic sickness, decreased IQ, and increased mortality. Childhood lead exposure has been related to higher incidence of violent criminality decades later. Seizures, coma, and death can all result from high amounts of lead. Lower levels of lead exposure tend to cause less visible harm, but there is no such thing as a safe amount of lead exposure: scientists’ best opinion is that any lead exposure causes harm.

Many of the risks associated with lead have been known for decades. In the 1920s, a General Motors research facility invented leaded gasoline, and people were already observing that youngsters exposed to high quantities of lead had terrible health implications. However, the inventor of leaded gasoline, Thomas Midgley Jr., ran a campaign to persuade the world that it was safe. (Midgley also produced CFCs, ozone-depleting refrigerants that were eventually prohibited by the Montreal Protocol in 1987; he’s been dubbed a “one-man environmental disaster.”) )

Rich countries began to address the problem in the 1970s, after additional studies established the dangers of lead. In the United States, the Clean Air Act set limits on lead emissions, and the Environmental Protection Agency mandated that gas stations supply unleaded gas as a first step toward phasing out leaded fuels a few years later.

Between 1976 and 1989, the amount of lead used in motor gasoline in the United States is estimated to have decreased by 99 percent, according to the EPA. Following that, blood lead levels were measured. The number of crimes has also decreased. Those gains were accomplished despite the fact that lead, which was used in gasoline (as well as paint and other consumer products) prior to restrictions, is still present in our soil and dust, posing a huge public health threat.

The EPA outlawed leaded gasoline for on-road automobiles in 1996. During the same time period, Japan and Europe issued their own restrictions. China and India followed in the year 2000.

How the United Nations phased out leaded gasoline worldwide

Leaded gasoline was still in use in 117 nations around the world, mostly in low-income countries.

The Partnership for Clean Fuels and Vehicles, created by the United Nations Environment Program (UNEP) in 2002, is a long-term initiative to phase out leaded gasoline.

Its tactics were quite flexible: convincing governments of policy bans, teaching businesses how to make cleaner vehicles, finding investment for better refineries, and, in one case, navigating a massive bribery scandal, when it turned out that a leaded gasoline producer, the chemical company Innospec Ltd., was fighting to keep its product legal in Indonesia.

In Sub-Saharan Africa, where 25 countries signed on to a plan to de-lead their gasoline in 2005, the UN’s effort was quickly adopted. It moved more slowly in other parts of the world, particularly in the Middle East, where many governments possessed massive inventories of leaded gasoline.

In 2011, Peter L. Tsai and Thomas H. Hatfield calculated that eliminating leaded gas would boost world GDP by 4%, or $2.4 trillion (counting health savings as well as social benefits from higher IQ and lower crime).

They also calculated that the direct benefits in terms of lives saved would be 1.2 million per year. They conclude that eliminating lead from gasoline has been the “single most essential technique” for combating lead poisoning, with “economic gains exceeding expenses by more than 10 times.”

While there is much discussion among academics about the actual degree of lead’s effect on crime, there is no doubt that moving away from lead fuels is cost-effective: Poisoning your entire population is a horrible idea, and switching to non-leaded fuels is one of the most cost-effective strategies to prevent lead poisoning.

Only sections of Algeria, Iraq, Yemen, Myanmar, North Korea, and Afghanistan have legalized automobile leaded gasoline by 2014.

Algeria, Yemen, and Iraq were the only countries left in 2016. And today, two decades after the campaign began, unleaded gas will be used in cars all around the world.

The road ahead

The elimination of leaded gasoline in automobiles is a significant achievement that deserves to be celebrated. However, there is still a long way to go in the struggle to eliminate lead poisoning’s negative impacts on our environment and future generations.

Leaded gasoline in automobiles has been outlawed in the United States for more than 25 years. The lead from that gasoline, however, has accumulated in the soil and dust, and it is still harming children today.

Lead exposure is monitored by the Centers for Disease Control and Prevention (CDC) across the United States. In 2018, the most recent year for which data is available, it was discovered that between 1 and 5% of children in most states had blood lead levels of more than 5 micrograms per deciliter, which could cause major health problems and long-term injury. (Today’s children in the United States are largely exposed to lead through soil and dust consumption.) Because lead paint is used in historic dwellings, dust often contains lead.)

UNICEF estimates that one in every three children in the world has lead levels above the 5 g/dL limit. Heavy industry, insufficient battery recycling and disposal, crumbling pipelines, and lead-based ceramic glazes, for example, are all factors that contribute to elevated lead levels in urban areas.

Lead-based fuels are still authorized in aviation and a few other specialized situations in the United States, despite the fact that they are forbidden on the road, and there is no serious progress toward phasing them out. Even while they provide far less lead exposure than vehicle leaded gasoline, the fact that there is no known safe limit of lead exposure should prompt us to be cautious – even minor exposures from these less common sources might create issues.

The elimination of leaded gasoline in all countries will help a lot in the fight against lead poisoning, but it should be complemented with steps to combat the various ways lead enters children’s bodies. The bipartisan infrastructure bill currently being debated in the US Congress contains funding for lead remediation and pipe replacement, but it is unlikely to be enough to replace all of the country’s outdated lead pipes.

UNICEF recommends “totally eliminating the possibility for lead exposure in locations where children live, play, and learn,” which would be a huge investment with a huge payoff. Poisoning the next generation is shortsighted, and investing in lead prevention is an investment in our future.

Celebrating and learning from humanity’s achievements

The United Nations is regularly condemned as “bloated, undemocratic,” incapable of leading us toward real solutions, and not focusing on the world’s most pressing issues.

However, the worldwide elimination of leaded gasoline in automobiles is a genuine achievement worth celebrating and examining to see how the world can apply the tactics that were successful in combating leaded gasoline to the other massive problems that require international coordination that we face in the twenty-first century.

The team working on it has already shifted its focus to the next critical transition for road vehicles: the transfer from gasoline-powered vehicles to low- and zero-emission alternatives. In a news release accompanying the announcement, UNEP Director Andersen said that the leaded-gas project “is testament to the strength of multilateralism to drive the world towards sustainability and a cleaner, greener future.” “Through a rapid transition to clean vehicles and electric mobility, we are energised to shift humanity’s future for the better.”

They’re also working to phase out lead paint, which is another big source of lead exposure in the home.

The UN’s road map for combating leaded gasoline a combination of technological solutions that made it easier to switch away from lead in engines, political coalition-building, business partnerships, and a few prosecutions of bad actors who used bribery to keep lead in business can also be applied to climate change challenges.

Separate from all of that, it’s also worth celebrating humanity’s triumphs over death, disease, and our own self-inflicted miseries. One of the worst blunders of the twentieth century was the widespread use of leaded gasoline. Ending it is one of the first major worldwide victories of the twenty-first century.

Before, what was the point of adding lead in gasoline?

The elimination of harmful exhaust emissions from cars and trucks has been a cornerstone of US environmental policy. Air pollution in the urban environment have been reduced by millions of tons thanks to EPA rules on mobile sources. Octane has been the subject of several EPA gasoline restrictions. Octane is a gasoline ingredient that is required for modern engines to work properly. Octane has been produced in a variety of ways over the years, including renewable and petroleum-based sources. Lead, methyl tertiary butyl ether (MTBE), benzene, toluene, ethyl-benzene, and xylene (BTEX), as well as ethanol, are among them (a biofuel). Lead and petroleum-based octane suppliers have been eliminated from the fuel supply or reduced as negative health and environmental effects have been revealed. The BTEX complex (a petroleum refining product generally referred to as gasoline aromatics) and ethanol are the two principal sources of octane used in the United States today.

The ability of a fuel to avoid knock is measured by its octane rating. Knock happens when fuel is ignited early in the engine’s cylinder, reducing efficiency and potentially damaging the engine. Knock is a term that most current drivers are unfamiliar with. This is due to the presence of an oxygenate in the fuel, which reduces knock by supplying oxygen to the fuel. Octane is the popular name for this oxygenate.

Most retail gas stations provide three octane grades: 87 (normal), 89 (mid-grade), and 91-93 (high-grade) (premium). The octane number indicates how resistant the fuel mixture is to knocking. Higher compression ratios, turbocharging, and downsizing/downspeeding are all possible with higher octane fuels, resulting in improved engine efficiency and performance. High-octane gasoline is now marketed as “premium,” although automakers have expressed interest in boosting the minimum octane pool in the United States to allow for smaller, more efficient engines. This would improve vehicle efficiency while also lowering greenhouse gas emissions by reducing fuel consumption.


Automobile makers were looking for a chemical that would lessen engine knock in the early twentieth century. In 1921, General Motors engineers discovered that tetraethyl lead (commonly known as lead) added octane to gasoline, avoiding engine knock. While aromatic hydrocarbons (such as benzene) and alcohols (such as ethanol) were also known to provide octane at the time, lead was favored due to its lower cost of manufacturing. Until the mid-1970s, when the US Environmental Protection Agency (EPA) began phasing it out due to documented negative health effects, leaded gasoline was the most common fuel type in the United States.

Health concerns about lead in gasoline were highlighted early on in its use as a fuel additive. In 1924, 15 refinery workers died of probable lead poisoning in New Jersey and Ohio. As a result, the Surgeon General put a temporary halt to the production of leaded gasoline and formed a team to look into the potential effects of lead in gasoline. While the panel found no evidence of lead poisoning over a short period of time, it warned that prolonged lead exposure could cause “chronic degenerative disorders of a less evident type.”

Despite these concerns, the Surgeon General established a voluntary lead content threshold, which the refining sector has met successfully for decades. The fatal health effects of low-level lead exposure were not discovered until the 1960s, after intensive health research. Low-level, ambient lead exposures are especially harmful to children’s developing bodies. Anemia, behavioral issues, low IQ, reading and learning impairments, and nerve damage are among health effects of lead exposure in children. Lead poisoning is linked to hypertension and cardiovascular disease in adults. The overall amount of lead used in gasoline was over 200,000 tons per year prior to the lead phase-out.

In 1970, Congress passed the Clean Air Act, which paved the way for the creation of the Environmental Protection Agency and, eventually, the removal of lead from gasoline. According to the EPA, 68 million children were exposed to dangerous levels of lead from leaded gasoline alone between 1927 and 1987. Between 1970 and 1987, the phase-out of lead in gasoline lowered the number of children with dangerous levels of lead in their blood by 2 million each year.

The Clean Air Act is passed by Congress in 1970. The Environmental Protection Agency (EPA) is established and granted the ability to regulate substances that damage human health.

1973: The EPA mandates a gradual reduction in lead levels in all gasoline grades.

In order to be compatible with 1975 make and model year automobiles, the EPA requires that at least one grade of unleaded gasoline be available. The catalytic converters employed in these new vehicles to regulate exhaust emissions are damaged by lead. Vehicles with catalytic converters are still on the road today.

The EPA bans the use of leaded gasoline in on-road automobiles in 1996. (leaded gasoline was down to 0.6 percent of 1996 gasoline sales). Some aircraft fuels still contain lead.

Lead is no longer present in gasoline in most parts of the world, thanks to concerted efforts. Following the phase-out of lead in the United States, the oil refining industry decided to build more refining capacity to make octane from other petroleum products rather than renewable sources like ethanol.

Methyl Tertiary Butyl Ether (MTBE)

The Clean Air Act Amendments of 1990 (CAAA) were the next major fuel restriction. CAAA mandates the use of reformulated gasoline in places that do not meet ground-level ozone requirements, among other things (RFG). RFG has a higher oxygenate concentration, which aids in full combustion. As a result, during combustion, RFG reduces the generation of ozone precursors and other air toxics.

Because of its ease of shipping and mixing, a petroleum derivative, methyl tertiary butyl ether (MTBE), was utilized in 87 percent of RFG by the late 1990s. Ethanol was a more common component of RFG in the Midwest. MTBE was taken out of the gasoline pool despite its success in lowering ozone precursors owing to worries about its solubility in water, which resulted in the poisoning of water supplies in several states. According to the EPA, MTBE was not utilized in large quantities in the United States as of 2005. Reformulated gasoline accounts for 30% of all gasoline sold in the United States. The extra octane required by RFG is provided by ethanol.

1998: The Environmental Protection Agency (EPA) convenes a Blue Ribbon Panel, which concludes that MTBE poses a threat to groundwater resources. The United States Geological Survey (USGS) discovered MTBE in 20% of groundwater supplies in RFG zones at the time.

The EPA announces the phase-out of MTBE in order to preserve drinking water in the year 2000. At the same time, the Environmental Protection Agency (EPA) and the United States Department of Agriculture (USDA) advocate for a greater usage of ethanol to protect air quality.

From 2000 to 2005, seventeen states outlawed or severely restricted the use of MTBE in gasoline pools.

The BTEX Complex

A hydrocarbon combination of benzene, toluene, xylene, and ethyl-benzene makes up the BTEX complex. These compounds, often known as gasoline aromatics, are processed from low-octane petroleum products to create a high-octane gasoline additive. While some BTEX is naturally present in gasoline, it is also added to finished fuel to increase its octane rating. The overall amount of BTEX (aromatics) in finished gasoline is determined by the octane value and other fuel qualities needed.

The increase in BTEX in gasoline was a result of the phase-out of lead. When it came to replacing lead as the principal source of octane in gasoline, refiners had two options: BTEX or ethanol. To replace lead with BTEX, a high-octane petroleum refining product, the refining sector invested in more refining capacity. By 1990, BTEX had risen from 22% to almost a third of the gasoline pool as a result of its replacement for lead. The BTEX volume percentage in premium gasoline grades reached as high as 50%. The EPA has lowered the volume of aromatics in normal gasoline to between 25 and 28 percent of the pool through reformulated gasoline and other efforts, while some health professionals dispute the safety of even these levels.

There were early concerns about the BTEX complex after the lead phase-out. Senator Tom Daschle stated his alarm about gasoline aromatics in 1987, saying, “In the gasoline industry, a revolutionary change is taking place that poses a severe threat to the environment and human health: rising concentrations of benzene and other aromatics.”

Even very low-level exposure to the BTEX complex from gasoline additives and other petroleum products, according to current health studies, may cause detrimental developmental, reproductive, and immunological reactions, as well as cardio-pulmonary impacts. Ultra-fine particles (UFP) and polycyclic aromatic hydrocarbons (PAHs) are generated when the BTEX complex in gasoline is incompletely burned, and they have their own negative health effects even at low levels. UFP and PAHs are mutagenic and carcinogenic. Both UFP and PAHs have been related to developmental and neurological problems, as well as cancer and cardio-pulmonary consequences. Because benzene is so harmful, it has received a lot of attention in the gasoline industry. At the same time, partial replacement of benzene with other aromatic chemicals (xylene, ethyl-benzene, toluene) might not be enough to reduce BTEX exposure.

1990: The Clean Air Act Amendments are passed by Congress, requiring, among other things, that benzene levels in locations that do not meet ground-level ozone criteria be reduced. S.1630, the Clean Octane Amendment, was included in the CAAA and grants the EPA the ability to employ “to replace the hazardous aromatics that are now used to raise octane in gasoline with non-toxic additives.”

2007: The Environmental Protection Agency (EPA) modifies the Control of Hazardous Air Pollutants from Mobile Sources (MSAT2), lowering the overall concentration of benzene in gasoline to 0.62 percent, down from 1.3 percent on average. Toluene and xylene, for example, are not capped aromatics.


Plant-based alcohol fuels, such as ethanol, piqued the curiosity of early automakers. The first Model T to run on ethanol was designed by Henry Ford. However, gasoline was a more cheaper fuel at the time. Standard Oil was also “hesitant… to promote the development and distribution of a competing fuel produced by a business unrelated to petroleum.” Since then, the petroleum industry has dominated the fuels market.

During the 1973 oil embargo, ordinary unleaded gasoline prices rose by 57%, and there were regular gasoline shortages. These events generated fresh interest in fuel efficiency, electric vehicles, and renewable fuels like ethanol, which were considered as methods to fulfill the new restrictions and minimize petroleum consumption. In the United States, the bulk of ethanol is now combined with gasoline to make E10 (10 percent ethanol, 90 percent gasoline). E10 is found in almost 95% of gasoline sold in the United States.

Ethanol is a great octane supplier, with neat (pure) ethanol having an octane rating of over 100, in addition to having lower lifecycle greenhouse gas emissions than conventional gasoline. Refineries currently produce’sub-octane gas,’ which has a lower octane value than what is required. The cheapest octane source, ethanol, is then utilized to raise the gasoline’s octane rating up to the indicated octane value on the gas pump. For example, to meet the minimum octane requirement of 87 for retail gasoline, 84 octane gasoline is commonly blended with 10% ethanol.

Increasing the octane content of gasoline currently has two options: increasing the volume of gasoline aromatics or increasing the volume of ethanol.