Effects of Menthol Vapor on the Intact Animal with Special Reference to the Upper Respiratory Tract*

Rats were exposed to menthol vapor of various concentrations for a period from seventy-one to seventy-nine days and a study was made of the over-all effects. It was found that there were no gross toxic effects, but a histopathological examination of organ tissues revealed that changes indicative of irritation had occurred in the lungs of animals exposed to the highest concentration of menthol.