As leaded gasoline became widespread, concerns about lead poisoning in urban environments began to grow. Studies linked lead exposure to neurological damage, particularly in children.

Due to mounting evidence of its harmful effects, leaded gasoline was gradually phased out in many countries starting in the 1970s. The United States completely banned leaded gasoline for on-road vehicles in 1996.

Scientists discovered that CFCs released into the atmosphere were depleting the ozone layer, which protects the Earth from harmful ultraviolet radiation. This discovery raised serious environmental concerns.

The Montreal Protocol, an international treaty, was signed in 1987 to phase out the production and use of ozone-depleting substances, including CFCs. This agreement marked a global effort to address the environmental damage caused by Midgley's invention.

Despite the phase-out of leaded gasoline and CFCs, their legacy continues to impact the environment and public health. Lead contamination remains a problem in some areas, and the long-lived nature of CFCs means that they will continue to affect the ozone layer for many years to come.