John H. Sinfelt, a chemical engineer whose research for an oil company helped lead to the introduction of unleaded gasoline and significant reductions in air pollution, died on May 28 in Morristown, N.J. He was 80.

The cause was complications of congestive heart failure, his son, Klaus, said.

In the late 1960s and ’70s, the petroleum industry was under intense pressure to produce gasoline without lead, which contributed to air pollution and posed substantial health risks, particularly to children. Lead was added to gasoline to raise octane levels, which helped keep engines from knocking.

The Environmental Protection Agency issued regulations calling for a gradual reduction in the lead content of gasoline in 1973.