The actor originally cast as the Tin Man, though Kari doesn't name him, was Buddy Ebsen. And the original Tin Man makeup he wore was pure aluminum dust. Breathing the dust coated his lungs with aluminum and he became severely ill. He was taken to the hospital in critical condition and his treatment and recovery took six weeks. And although he never appears on screen, Ebsen's vocals can still be heard in the group songs featuring the Tin Man, as they were recorded before filming his scenes.
Jack Haley was called in to replace Ebsen as the Tin Man, and the makeup was changed to an aluminum paste applied over white clown makeup to protect the skin. This prevented the lung irritation from airborne aluminum powder, but Haley still suffered from an eye infection caused by the new makeup.
In 2007, an inmate named John Galvan happened to see the Mythbusters episode debunking the movie cliche of igniting gasoline with a lit cigarette, which was the basis for his false conviction in a 1986 arson/murder. Galvan used the episode to prove he had been coerced into confessing to a physical impossibility. After a long legal battle, he was released in 2022.