Leaded-gasoline phaseout (United States, 1923 to 2021)

Lead was added to U.S. gasoline from 1923; after the 1970 Clean Air Act, EPA began cutting it in 1973, a court upheld that power in 1976, a statutory ban for road vehicles took effect January 1, 1996, and children's blood lead fell sharply, though paint, dust and water also matter and uneven exposure and aviation fuel remain.

The record

Introduction and early warnings

• General Motors researchers found in December 1921 that tetraethyl lead improved fuel anti-knock performance. Leaded gasoline reached the market in February 1923. In October 1924 workers at Standard Oil's Bayway, New Jersey, refinery developed severe lead poisoning; seven died and 33 were hospitalized, according to a history by William Kovarik, and New York City, Philadelphia and New Jersey briefly barred sales. (Kovarik, International Journal of Occupational and Environmental Health, 2005, summary page; opened. The journal article itself was not opened.)
• A 1925 Public Health Service panel reviewed limited studies. In January 1926 it found "no good grounds" to ban leaded gasoline for the time being and said research should continue. Kovarik argues that industry-funded science, led by Robert Kehoe of Ethyl Corporation, shaped the field for decades. Ethyl and industry disputed the harm. (Kovarik summary; EPA Journal, May 1985, below)

Federal action

• The Clean Air Act of 1970 and the catalytic converter drove the shift. EPA first announced a phase-out of lead in all gasoline grades on November 28, 1973. New cars with catalytic converters from the 1975 model year required unleaded fuel. (EPA history: lead; EPA release, Jan. 29, 1996; both opened)
• Industry challenged the early rule. In Ethyl Corp. v. EPA, No. 73-2205 (D.C. Cir. Mar. 19, 1976) (en banc), the court upheld EPA. The majority held the "will endanger" test in Clean Air Act Section 211(c)(1)(A) is precautionary and does not require proof of actual harm before regulation, writing that "danger is the product of magnitude of risk and magnitude of potential harm." The court upheld three EPA conclusions, including that dustfall posed a danger to children. Judges MacKinnon and Wilkey (joined by Tamm and Robb) dissented, arguing the record did not support the 40 micrograms per 100 grams finding and that the dustfall theory was speculative. An earlier panel opinion had favored the petitioners and was vacated. (Environmental Law Reporter summary; opened. The opinion itself was not opened.)
• On March 4, 1985 EPA set new limits. The cap on leaded gasoline fell from 1.1 grams of lead per gallon to 0.5 on July 1, 1985, then to 0.1 on January 1, 1986, a 90 percent cut. The rule let refiners bank and trade lead credits, which EPA estimated would save over $200 million. (EPA Journal, May 1985; opened. An EPA staff article, so the cost and benefit numbers below are the agency's own.)
• The 1990 Clean Air Act Amendments added Section 211(n), which made it unlawful after December 31, 1995 to sell or supply gasoline containing lead additives for use in motor vehicles. EPA's 1996 rule implemented the ban, removed obsolete reporting rules and "unleaded only" labels, and noted that total lead use in gasoline had fallen to under 1 percent of its 1970 peak by 1988. Leaded fuel remains allowed for aircraft, racing and some nonroad engines. (Federal Register, Feb. 2, 1996; opened)

Timeline

Exposure and blood lead data

• National survey (NHANES II) data show the mean blood lead level fell 36.7 percent from February 1976 to February 1980, from 15.8 to 10.0 micrograms per deciliter. CDC said the authors ruled out season, income, region, urban or rural residence, laboratory error and chance, and that the drop "reflects the decrease in lead used in gasoline production." CDC also noted 502,900 children screened in 1980, with 26,500 identified as having lead toxicity. (CDC, MMWR, Mar. 19, 1982; opened)
• EPA's children's indicator: median blood lead for ages 1 to 5 was 0.6 micrograms per deciliter in 2017 to 2020, down 96 percent from 1976 to 1980. The 95th percentile was about 2, down 93 percent. EPA says the largest drop came from the 1970s to the 1990s, after lead was removed from gasoline, and levels kept falling afterward. (EPA, Biomonitoring: Lead; opened)
• In EPA's 1996 release, Administrator Carol Browner said blood lead in children had dropped 70 percent and called the removal "one of the great environmental achievements of all time." Average gasoline lead in 1973 was 2 to 3 grams per gallon (about 200,000 tons of lead a year); by 1995 leaded fuel was 0.6 percent of sales (under 2,000 tons). (EPA release 1996)

Disputed or differing numbers

| Item | Figure A | Figure B | Notes | |---|---|---| | Decline in children's blood lead | 70 percent (Browner, 1996, a mid-1990s statement) | 96 percent for median, 1976 to 1980 to 2017 to 2020 (EPA indicator) | Different end dates and statistics; not conflicting | | Mean blood lead, 1976 to 1980 | 15.8 to 10.0 µg/dL, all ages (MMWR 1982) | Age 1 to 5 median not stated in the pages we read | Different groups | | Link of gasoline lead to blood lead | Elasticity about 0.55, about 0.84 without NY, CA and DC (Reyes) | CDC: drop "reflects" gasoline decrease, other explanations ruled out (MMWR 1982) | Same data period, different method | | Share of violent crime decline due to lead | About 56 percent, 1992 to 2002 (Reyes, 2007) | 0 to 5 percent of 1990s homicide decline using the strongest studies; 3 to 36 percent using all (meta-analysis cited by VerBruggen) | Contested | | 1985 net benefits | $264 million, 1985 (excluding blood pressure) | $1,988 million including blood pressure (EPA Journal) | EPA called the blood pressure link "unproven" |

Costs, who paid and what remains

• EPA's own 1985 estimates: total benefits excluding blood pressure of $360 million (1985), $1,924 million (1986), $1,799 million (1987); refining costs $96 million, $608 million, $558 million; net benefits $264 million, $1,316 million and $1,241 million. Including blood pressure, net benefits were $1,988 million, $7,213 million and $6,916 million. EPA projected about 172,000 fewer children above 25 micrograms per deciliter in 1986. EPA's Goldstein said the blood pressure research on white males aged 40 to 59 was preliminary and a causal role unproven. (EPA Journal 1985)
• Refiners were expected to pass higher costs to consumers at the pump. EPA estimated 16 percent of vehicles were misfueled, at least 28 percent had emission controls removed or disconnected, and leaded gasoline was about 7 cents a gallon cheaper than unleaded regular. Industry and the lead industry disputed the health case. (EPA Journal 1985)
• Exposure from other sources persists. EPA lists house dust from deteriorated lead paint, drinking water from corroding pipes, contaminated soil, and outdoor air near smelters, mines, batteries and airports. For 2015 to 2020, median blood lead was 0.8 micrograms per deciliter for Black non-Hispanic children, higher than other groups, and 0.8 for children in families below the poverty level versus 0.6 at or above it. The 95th percentile was 2.8 below poverty versus 2.2 above. EPA says no safe level has been identified. (EPA indicator)
• Leaded aviation gasoline: EPA's October 18, 2023 final endangerment finding says piston-engine aircraft release about 70 percent of lead in the air, and over 5 million people, including more than 360,000 children under 5, live near an airport where such aircraft operate. (Earthjustice summary of the EPA announcement; opened. Earthjustice is an advocacy group; the EPA text was not opened.)
• Global: the UN Environment Programme said the world's last leaded petrol use ended in August 2021 with Algeria, and estimated 1.2 million premature deaths avoided and $2.4 trillion in annual benefits. These are UNEP estimates as reported by National Geographic. (National Geographic, Sept. 1, 2021; opened)

What this case shows

1. The question was settled in public: a court and a rulemaking. Anyone could read EPA's health documents and comments, and the D.C. Circuit's 1976 decision lets regulators act on risk before harm is proven. That standard turned a scientific dispute into a legal rule the public can invoke. (ELR summary)
2. Public data made the result visible. A national health survey, repeated over time, showed blood lead falling as gasoline lead fell. CDC published it in 1982 and EPA keeps the series. Ordinary readers can check it. (MMWR 1982; EPA indicator)
3. The cost was disclosed, and so were the guesses. EPA published a table of costs and benefits in 1985 and labeled the blood pressure benefit "unproven." The public could see which part of the benefit rested on strong evidence. (EPA Journal 1985)
4. The benefit was not equal, and the leftover burden is not equal. Children in cities near heavy traffic gained most from a drop in air lead, but today Black and low-income children still have higher median levels. (EPA indicator)
5. For decades the evidence was shaped by those who sold the product. The 1926 panel finding and Kehoe's role show how industry-funded science set the terms, and the public learned this much later. (Kovarik)

The strongest objections, and our answers

1. Objection: Blood lead fell for many reasons, not just gasoline. True: paint rules, water, screening and soil work also changed. Mitigation: CDC's 1982 report says other explanations it could test were ruled out for 1976 to 1980, but EPA's own page lists several other sources. We state that the large drop followed gasoline removal but do not assign a share to gasoline.
2. Objection: The crime-reduction claim is overreach. Reyes (2007) estimates lead explains about 56 percent of the fall in violent crime from 1992 to 2002, with weaker results for murder and none for property crime. A meta-analysis cited by VerBruggen puts the share at 0 to 5 percent using the strongest studies. Mitigation: We do not rely on the crime claim. It appears only to show the dispute and that the reported range is wide.
3. Objection: The 1985 benefit numbers are agency projections. Mitigation: Agreed, and we label them EPA's. The article itself says the blood pressure benefit was unproven. We do not use the benefit-cost ratio as a result.
4. Objection: The regulation imposed costs on refiners and drivers and was driven by a technology (catalytic converters) as much as by health. Mitigation: EPA estimated refining costs of $96 to $608 million a year and a price gap that led to misfueling. The 1973 rule and the converter requirement came together. We report both and do not claim health was the only driver.
5. Objection: Kovarik's account is one historian's view of industry conduct. Mitigation: It is a secondary source, in a journal, and agrees with the 1985 EPA Journal on the 1926 panel date and the 1925 suspension. We attribute the characterization of industry conduct to the author.

Open questions: what would change our minds

• The Ethyl v. EPA opinion, the 1973 and 1985 Federal Register rules, and the Clean Air Act text were not opened. We used a summary of the case, the EPA Journal and a 1996 notice. Unverified against the originals.
• EPA's own 1985 regulatory impact analysis was not found; the numbers come from an agency staff article.
• Kovarik's account (deaths, panel finding, Kehoe) was read as a summary page, not the journal article. The details of the 1924 events are unverified.
• The claim that gasoline lead alone explains a given share of the blood lead drop was not tested; the one national-survey comparison used (MMWR 1982) covers 1976 to 1980 only.
• The Reyes (2007) paper and a VerBruggen brief were read, but the meta-analysis cited in the brief was not opened. The 0 to 5 percent and 3 to 36 percent figures are as reported by VerBruggen.
• The Clair Patterson and Herbert Needleman studies were not read.
• The 2023 aviation finding was read through an advocacy group's release. The EPA document was not opened.
• UNEP's 2021 estimates (1.2 million deaths, $2.4 trillion annually) were not checked against a UNEP document, and National Geographic does not say whether the deaths figure is annual.
• Costs borne by drivers with older vehicles (valve seat wear, lead substitute additives) and by workers who made lead additives were not quantified.
• A peer-reviewed paper on the national blood lead trend (an NHANES analysis on PubMed Central) could not be opened because of a verification page.

Sources

Found an error or a better source? We keep every correction on the record with its date and reason. Nothing here is quietly rewritten.