Studies show that liquids in some e-cigs are associated with lung irritation and even some serious diseases. Diacetyl, a butter-flavored chemical, has been linked to bronchiolitis obliterans, which is a life-threatening obstructive lung disease. Jessica Barrington-Trimis, an epidemiologist at the University of Southern California, said the flavorings “have a history of being known respiratory toxins.”
Konstantions Farsalinos, a researcher at the Onassis Cardiac Surgery Center, uses e-cigs. He tested 159 sweet e-cig liquids and discovered that 74 percent contained diacetyl or a chemically similar substitute, acetyl propionyl. “Among the ones that tested positive, nearly half would expose users to levels that exceed recommended workplace limits for breathing the two chemicals,” Hiles writes.
While Diacetyl is safe to eat—it’s found in butter, beer and other foods—breathing it might not be safe. The National Institute for Occupational Safety and Health reported that eight workers in a Missouri popcorn plant got bronchiolitis obliterans—also called “popcorn lung”—as a result of breathing diacetyl during work in 2002. Five died from respiratory problems, and four of them needed lung transplants, Hiles writes.
Farsalinos believes acetyl propionyl and diacetyl should be removed from e-cig vapors because “it’s a 100 percent avoidable risk.” John Hallagan, senior advisor and general counselor of the Flavor and Extract Manufacturers Association, said, “When we saw flavors were being used in e-cigarettes, we wanted to put the word out right away that it’s a possibility that flavors being inhaled through an e-cigarette could also be harmful. Flavors are not meant to be inhaled.”