Update on flavoring-induced lung disease

Curr Opin Pulm Med. 2016 Mar;22(2):158-64. doi: 10.1097/MCP.0000000000000250.


Purpose of review: Since the initial report of bronchiolitis obliterans in microwave popcorn workers, exposures to flavoring substances have been identified in a variety of food and flavor manufacturing facilities and in the consumer market. Attempts to decrease the risk of lung disease have included the use of flavoring substitutes; however, these chemicals may cause similar injury. This article reviews recent flavoring exposures and data on the pathogenesis, clinical characteristics, and surveillance of flavoring-induced lung disease.

Recent findings: Diacetyl and 2,3-pentanedione exposures have occurred in food production facilities that make cookies, cereal, chocolate, and coffee. Airborne levels often exceed proposed occupational exposure limits. Cases of biopsy-proven bronchiolitis obliterans in heavy popcorn consumers have also been reported. New data demonstrate the presence of diacetyl and 2,3-pentanedione in flavored nicotine liquids used in electronic nicotine delivery systems.

Summary: Diacetyl substitutes cause similar peri-bronchiolar fibrotic lesions in animal studies. Their use may continue to place workers at risk for flavoring-induced lung disease, which may present in forms beyond that of fixed airflow obstruction, contributing to delays in identifying and treating patients with flavoring-induced lung disease. Engineering controls, medical surveillance and personal protective equipment can limit flavorings exposure and risk for lung disease.

Publication types

  • Review

MeSH terms

  • Animals
  • Diacetyl / toxicity*
  • Flavoring Agents / toxicity*
  • Humans
  • Lung Diseases / chemically induced*
  • Pentanones / toxicity*
  • Risk


  • Flavoring Agents
  • Pentanones
  • Diacetyl
  • 2,3-pentanedione