Why did countries phase out tetraethyl lead in automobile gasoline?

Countries phased out the use of tetraethyl lead (TEL) in automobile gasoline primarily due to its detrimental impact on public health and its incompatibility with modern vehicle technology.1

The decision was driven by two main factors:

• Environmental and Health Concerns: Research, including studies by geochemist Clair Patterson and pediatrician Herbert Needleman, highlighted the dangers of lead poisoning caused by the accumulation of lead in the environment and human tissues. Exposure to lead particulates from exhaust fumes was particularly harmful to children, leading to learning disabilities, neurological damage, and other severe health complications.123
• Technological Interference: In the United States, the Environmental Protection Agency initiated the phase-out in 1972 because lead interfered with the function of catalytic converters. These smog-reducing devices, which became standard in new cars starting in 1975, were rendered ineffective by the presence of lead in fuel.1

Following these developments, the use of leaded gasoline was progressively restricted and eventually banned globally for use in passenger automobiles.13