Studies conducted in 1942 by Dr. Oswald Hope Robertson of University of Chicago's Billings Hospital showed vaporized propylene glycol inhalation in laboratory mice may prevent pneumonia, influenza, and other respiratory diseases. Additional studies in monkeys and other animals were undertaken to determine longterm effects, especially the potential for accumulation in the lungs. After a few months of treatment, no ill effects were discovered.
Just found this for the first time if it was posted elsewhere.
Propylene glycol - Wikipedia, the free encyclopedia
Yet it will kill your cat dead......