, The notion that vaping causes "popcorn lungs" due to diacetyl in e liquids is based on outdated information. , ., While diacetyl was once used as a flavoring agent in some e liquids and linked to Diacetyl: Is it a danger for the e liquid? Our expert advice! A&L Community Request Diacetyl Center for Research on Ingredient Safety Research indicates that certain flavoring chemicals used in e cigarettes can irritate lung tissue and trigger inflammatory responses in laboratory settings. Some compounds, such as diacetyl, have been linked to respiratory damage when