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Necrosis of nasal and airway epithelium in rats inhaling vapors of artificial butter flavoring.
Hubbs AF; Battelli LA; Goldsmith WT; Porter DW; Frazer D; Friend S; Schwegler-Berry D; Mercer RR; Reynolds JS; Grote A; Castranova V; Kullman G; Fedan JS; Dowdy J; Jones WG
Toxicol Appl Pharmacol 2002 Dec; 185(2):128-135
As the result of a high prevalence of fixed airways obstruction in workers at a microwave popcorn manufacturing plant, we examined the hypothesis that vapors of butter flavoring used in the manufacture of microwave popcorn and other foods can produce airway injury in rats. Rats were exposed to vapors liberated from heated butter flavoring. Rats were exposed for 6 h by inhalation and were necropsied 1 day after exposure. The exposure was found by GC-MS analysis to be a complex mixture of various organic gases with the major peaks consisting of diacetyl (2,3-butanedione), acetic acid, acetoin (3-hydroxy-2-butanone), butyric acid, acetoin dimers, 2-nonanone, and delta-alkyl lactones. Diacetyl was used as a marker of exposure concentration. In the lung, butter flavoring vapors containing 285-371 ppm diacetyl caused multifocal, necrotizing bronchitis, which was most consistently present in the mainstem bronchus. Alveoli were unaffected. Butter flavoring vapors containing 203-371 ppm diacetyl caused necrosuppurative rhinitis, which affected all four levels of the nose. Within the posterior two nasal levels (T3 and T4), necrosis and inflammation was principally localized to the nasopharyngeal duct. Control rats were unaffected. Therefore, concentrations of butter flavoring vapors that can occur during the manufacture of foods are associated with epithelial injury in the nasal passages and pulmonary airways of rats.
Laboratory-animals; Animal-studies; Food-additives; Pulmonary-system-disorders; Respiratory-system-disorders; Nasal-cavity; Nasal-disorders; Nasal-disorders; Airway-obstruction; Humans; Vapors; Bronchial-asthma; Lung; Food-processing-workers; Author Keywords: flavoring; diacetyl; butter; popcorn; lung; nose; bronchitis; airway obstruction
Health Effects Laboratory Division, National Institute for Occupational Safety and Health1, Centers for Disease Control and Prevention, 1095 Willowdale Road, Morgantown, West Virginia 26505
Issue of Publication
Research Tools and Approaches: Exposure Assessment Methods
Toxicology and Applied Pharmacology
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division