| Abstract |
In February 2017, the Health Hazard Evaluation Program of the National Institute for Occupational Safety and Health received a request from management at a coffee roasting, flavoring, and packaging facility regarding concerns about potential health effects from exposure to diacetyl and 2,3-pentanedione during coffee roasting, grinding, and flavoring. In August 2017, we conducted an industrial hygiene survey and ventilation assessment at the facility. The industrial hygiene survey consisted of the collection of air samples and bulk samples of coffee for the analysis of diacetyl, 2,3-pentanedione, and 2,3-hexanedione. We used continuous monitoring instruments to monitor total volatile organic compounds, carbon monoxide, carbon dioxide, temperature, and relative humidity in specific areas and during tasks. We also conducted a medical evaluation of employees that consisted of a health questionnaire and breathing tests. Forty-nine of the 51 full-shift personal samples collected during the industrial hygiene survey exceeded the NIOSH recommended exposure limit for diacetyl of 5 parts per billion, with a maximum concentration of 47.3 parts per billion. Thirty-six of the 51 fullshift samples exceeded the NIOSH recommended exposure limit for 2,3-pentanedione of 9.3 parts per billion, with a maximum of 177.9 parts per billion. We identified work tasks that resulted in relatively higher air concentrations of diacetyl and 2,3-pentanedione than other tasks. Specifically, grinding roasted coffee beans, flavoring roasted beans, cleaning the flavoring mixer, cleaning the grinder, and packaging coffee were associated with higher diacetyl and 2,3-pentanedione levels. We observed high instantaneous levels of diacetyl and 2,3-pentanedione during grinding of coffee, weighing of flavorings, flavoring coffee, and packaging ground coffee. Air levels of carbon monoxide collected on employees with duties that included grinding unflavored and flavored roasted beans exceeded the NIOSH ceiling limit of 200 parts per million. Carbon monoxide levels in the area near the packaging grinders also exceeded 200 parts per million. Carbon dioxide levels were low throughout most of the facility. Overall, the most commonly reported symptoms were associated with mucous membranes, specifically the eyes and nose. Some production employees reported their symptoms were caused or aggravated by green bean coffee burlap bags, dust, flavorings, grinding coffee, or packaging coffee. Wheezing or whistling in the chest, breathing trouble, and shortness of breath were the most commonly reported lower respiratory symptoms. Participants reporting a current asthma diagnosis or ever having a diagnosis of asthma were 4.1 and 3.1 times higher, respectively, compared with the U.S. population of the same age, race/ethnicity, sex, and cigarette smoking distribution. Participants also reported phlegm for three consecutive months 2.5 times more than expected compared with the U.S. population. Four (13%) of 30 participants had abnormal spirometry; two (6%) of 31 participants had high exhaled nitric oxide, a marker of allergic airways inflammation. We recommend implementing local exhaust and other ventilation changes, modification of work practices, training employees about workplace hazards, and respirator use. We also recommend instituting a medical monitoring program to identify any employees who may be developing work-related lung disease (e.g., asthma, obliterative bronchiolitis) and to help management prioritize interventions to prevent occupational lung disease.
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