In March 2006, NIOSH received a request for a Health Hazard Evaluation (HHE) from owners of Yatsko’s Popcorn, a small popcorn popping plant, located in Sand Coulee, Montana. The company had originally operated out of a smaller building from 1979 to 1999, when the operation was moved to the current location. The occupational exposure concerns cited in this request included flavoring chemicals from popcorn production activities; reported health concerns included breathing problems, shortness of breath, wheezing, tightness in the chest, and skin disorders. This request was based on health concerns following NIOSH investigations of fixed obstructive lung disease consistent with bronchiolitis obliterans in microwave popcorn plant workers associated with exposure to butter flavorings. We conducted an industrial hygiene survey at the popcorn popping plant on April 12 and 13, 2006. Air samples were collected for total and respirable particles, particle size distributions, volatile organic compounds, total hydrocarbons, ketones (diacetyl, acetoin, and 2-nonanone), inorganic acids, and acetaldehyde. Bulk samples of flavoring ingredients were collected and analyzed for the emission of volatile organic compounds (VOCs) on heating. We reviewed medical records for two former workers and one current worker and we interviewed two workers and the spouse of the other worker. In May 2006, subsequent to our survey, the plant closed its operation. The main findings from this HHE include: At this plant, popcorn was popped and bagged; powdered cheese and jalapeno pepper flavorings were manually applied to some of the popped popcorn. Popping and bagging operations were done approximately twice a week for 2 to 4 hours per day depending on orders. Popping was done in a small building with a wall exhaust fan; the worker wore a disposable dust mask during popping; however, this was not a NIOSH-approved respirator. Diacetyl was detected by gas chromatography with mass spectroscopy (GCMS) in vapors released from a bulk sample of flavored oil heated to 50°C in an analytical laboratory, although it was not a predominant volatile organic compound released from the oil. Diacetyl was also detected by GCMS in two- and four-hour area air samples. Concentrations were too low to be detected (less than approximately 0.01 parts per million (ppm) in four-hour personal and area air samples by NIOSH method 2257). Using a direct-reading instrument, a peak diacetyl concentration of 0.14 ppm was measured in the air directly above a heated container of butter-flavored oil. Aldehydes were the predominant type of VOC identified in area air samples. However, acetaldehyde concentrations were less than the detectable (0.09 ppm) or quantifiable (0.15 ppm) concentrations. Average area particle concentrations in air using gravimetric analysis were 2.72 milligrams per cubic meter of air (mg/m3) for total particles and 0.89 mg/m3 for respirable particles. Particle concentrations were higher during popcorn bagging activities than during other activities; particle concentrations were also higher on the day that powdered flavorings were applied to the popcorn than on the day when powdered flavorings were not used. Airborne exposures of this popcorn popping operation included lower diacetyl concentrations and more aldehyde compounds than was observed in microwave popcorn production. All three workers who worked at the company developed respiratory disease while working there. One former worker, who had only worked at the original smaller plant and who eventually died as a result of his respiratory disease, had airways obstruction that improved with a bronchodilator, which is consistent with asthma. Two other workers who had worked at both the original smaller plant and the current plant had symptoms of asthma; one of these had pulmonary function test results that improved significantly with a bronchodilator, which also is consistent with asthma. Some evidence suggests possible bronchiolitis obliterans in the worker who died and in one of the other two workers. While employed at the plant, all three workers experienced worsening of their respiratory symptoms the days they worked. NIOSH investigators found that aldehydes were the predominant type of volatile organic compound identified in air samples at the plant. Diacetyl was present in the air of the plant with a concentration too low to be quantified. Average area particle concentrations in air using gravimetric analysis were 2.72 mg/m3 for total particles and 0.89 mg/m3 for respirable particles. All three workers who worked at the plant developed respiratory symptoms while working there and had worsening of respiratory symptoms on days worked. Evidence from medical records and radiographs of these three individuals was consistent with asthma in all three workers and suggestive of possible bronchiolitis obliterans in two of the workers.
Region-8; Pulmonary-function-tests; Pulmonary-system-disorders; Volatiles; Organic-chemicals; Respirable-dust; Respiratory-irritants; Respiratory-system-disorders; Ketones; Chronic-inflammation; Lung-disease; Employee-exposure; Food-additives; Food-processing; Food-processing-industry; Food-processing-workers; Skin-irritants; Bronchial-asthma; Air-sampling
National Institute for Occupational Safety and Health, Division of Respiratory Disease Studies, 1095 Willowdale Road, Morgantown, WV 26505