National Institute for Occupational Safety and Health (NIOSH) investigations have shown that sufficient levels of work-related exposure to certain chemical vapors in flavorings can cause severe, irreversible lung disease. These chemicals, diacetyl and its closely related substitute 2,3-pentanedione, can be added to flavorings like the butter in microwave popcorn. The disease, technically called obliterative bronchiolitis, is sometimes called “popcorn lung” because scientists originally described it in workers who manufactured microwave popcorn.
A recent NIOSH study tested various coffee flavoring samples for these chemicals and compared the findings to ingredients on safety data sheets required by the Occupational and Health Administration (OSHA). Study lead author, Ryan LeBouf, NIOSH research industrial hygienist, explains the study published in the Annals of Work Exposure and HealthExternal.