Researchers at the University of California, Riverside, found that heating propylene glycol, the main ingredient in most e cigarette liquids, can produce two toxic chemicals, methylglyoxal and acetaldehyde, which damage lung cells. Using E liquide got tabac MB Hidden Formaldehyde in E Cigarette Aerosols New England Journal of Medicine Top 10 E liquide menthe All E Cigarettes Emit Harmful Chemicals, but Some Emit More Than Others Berkeley Lab Berkeley Lab News Center The Impact of E Cigarettes on the Lung Providers AmeriHealth Caritas Pennsylvania