Wikipedia relates:
Thioacetone has an intensely foul odor. Like many low molecular weight organosulfur compounds, the smell is potent and can be detected even when highly diluted. In 1889, an attempt to distill the chemical in the German city of Freiburg was followed by cases of vomiting, nausea and unconsciousness in an area with a radius of 0.75 kilometres (0.47 mi) around the laboratory due to the smell. In an 1890 report, British chemists at the Whitehall Soap Works in Leeds noted that dilution seemed to make the smell worse and described the smell as “fearful”. Thioacetone is considered a dangerous chemical due to its extremely foul odor and ability to render people unconscious, induce vomiting, and be detected over long distances.
Derek Lowe has written of this substance in Science, “Things I Won’t Work WIth: Thioacetone”.