title: Flavoring Chemicals in E-Cigarettes: Diacetyl, 2,3-Pentanedione, and Acetoin in a Sample of 51 Products, Including Fruit-, Candy-, and Cocktail-Flavored E-Cigarettes.
abstract: There are > 7,000 e-cigarette flavors currently marketed. Flavoring chemicals gained notoriety in the early 2000s when inhalation exposure of the flavoring chemical diacetyl was found to be associated with a disease that became known as "popcorn lung." There has been limited research on flavoring chemicals in e-cigarettes.
  
  
  
  We aimed to determine if the flavoring chemical diacetyl and two other high-priority flavoring chemicals, 2,3-pentanedione and acetoin, are present in a convenience sample of flavored e-cigarettes.
  
  
  
  We selected 51 types of flavored e-cigarettes sold by leading e-cigarette brands and flavors we deemed were appealing to youth. E-cigarette contents were fully discharged and the air stream was captured and analyzed for total mass of diacetyl, 2,3-pentanedione, and acetoin, according to OSHA method 1012.
  
  
  
  At least one flavoring chemical was detected in 47 of 51 unique flavors tested. Diacetyl was detected above the laboratory limit of detection in 39 of the 51 flavors tested, ranging from below the limit of quantification to 239 μg/e-cigarette. 2,3-Pentanedione and acetoin were detected in 23 and 46 of the 51 flavors tested at concentrations up to 64 and 529 μg/e-cigarette, respectively.
  
  
  
  Because of the associations between diacetyl and bronchiolitis obliterans and other severe respiratory diseases observed in workers, urgent action is recommended to further evaluate this potentially widespread exposure via flavored e-cigarettes.
  
  
  
  Allen JG, Flanigan SS, LeBlanc M, Vallarino J, MacNaughton P, Stewart JH, Christiani DC. 2016. Flavoring chemicals in e-cigarettes: diacetyl, 2,3-pentanedione, and acetoin in a sample of 51 products, including fruit-, candy-, and cocktail-flavored e-cigarettes. Environ Health Perspect 124:733-739; http://dx.doi.org/10.1289/ehp.1510185.
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Allen
authors.forename: Skye S
authors.initials: SS
authors.lastname: Flanigan
authors.forename: Mallory
authors.initials: M
authors.lastname: LeBlanc
authors.forename: Jose
authors.initials: J
authors.lastname: Vallarino
authors.forename: Piers
authors.initials: P
authors.lastname: MacNaughton
authors.forename: James H
authors.initials: JH
authors.lastname: Stewart
authors.forename: David C
authors.initials: DC
authors.lastname: Christiani
mesh_terms: D000093:Acetoin / Q000032:analysis; D003931:Diacetyl / Q000032:analysis; D066300:Electronic Nicotine Delivery Systems / Q000009:adverse effects / Q000706:statistics & numerical data*; D005421:Flavoring Agents / Q000009:adverse effects / Q000032:analysis*; D006801:Humans; D019570:Inhalation Exposure / Q000706:statistics & numerical data*; D010422:Pentanones / Q000032:analysis
chemical_list: D005421:Flavoring Agents; D010422:Pentanones; D000093:Acetoin; D003931:Diacetyl; C013186:2,3-pentanedione