Roasted coffee flavorings are appealing options to coffee consumers who may crave variety or avoid drinking black coffee. However, these flavorings contain alpha-diketones, hazardous chemical compounds that put coffee roasterie employees, and perhaps even flavored coffee consumers, at a serious risk of disease. Consider a study published by Bailey et al. in 2015: researchers tested thirteen former workers at a coffee roasterie and found that five of these former workers were diagnosed with obliterative bronchiolitis. All of those afflicted had worked in the coffee flavoring room. These workers should not have had such poor lung function; their ages ranged from just 25 to 42 years of age.
The National Institute for Occupation Safety and Health (NIOSH) cautions coffee roasterie workers about the risks of their work: the effects of their constant exposure to coffee dust, carbon dioxide, carbon monoxide and alpha-diketones range from mild respiratory symptoms to obliterative bronchiolitis, “a serious, often disabling, lung disease that involves scarring of the very small airways” (2019, p. 6). The injuries to the 25 to 42-year old’s in Bailey et al.’s study demonstrate just how hazardous alpha-diketones can be. Yet, there are numerous more studies with similar results.
A NIOSH Health Hazard Evaluation published as recently as 2019 noted that “to date, no cases of obliterative bronchiolitis have been reported in workers at coffee roasting and packaging facilities that produce only unflavored coffee” (p. 6). In the same evaluation (conducted 2016-2017) NIOSH found yet another roasterie employee who had worked with liquid flavorings before developing obliterative bronchiolitis. Whether the chemical was diacetyl, 2,3-pentanedione or carbon monoxide, employees working in the flavoring room of the roasterie exceeded recommended exposure limits by at least several hundred parts per billion (a max exposure of 2,127.7 ppb vs. 5.0 ppb recommended for diacetyl, a max exposure of 1,444.7 ppb vs. 9.3 ppb recommended for 2,3-pentanedione, and a max exposure of 29.8 ppb vs. 200 parts per million recommended for carbon monoxide). In total, 6% of employees had abnormal spirometry results and 8% of employees exhibited a marker of airway inflammation.
Even employees in small coffee roasteries are not safe from the health effects of these flavorings. To my knowledge, the first published evidence of obliterative bronchiolitis in a coffee roasterie included two disturbing case reports of employees who had worked in a small coffee-processing plant in Texas (NIOSH, 2013). In the first case, a nonsmoking, healthy, 34-year-old Hispanic women worked with roasted coffee flavorings for just a year before becoming so sick that she needed a lung transplant. The second case was similar. A nonsmoking, healthy, 39-year-old Hispanic man worked in the same facility for 19 months before developing obliterative bronchiolitis.
Though I have visited coffee roasteries from Ohio to Amsterdam, I have only once seen workers wearing personal protective equipment either while roasting or flavoring coffee. I doubt that production workers agitating bags filled with pounds of concentrated liquid flavoring mixed with roasted coffee are even aware of the combined health hazards of roasting, grinding and flavoring coffee. Even if a roasterie manager was cognizant enough of these risks to purchase a P95 or VOC mask, the CDC notes that personal protective equipment is actually “the least effective means for controlling hazardous respiratory exposures…” (2019, p. 37). The best options, according to the CDC, include engineering and administrative controls that focus on increasing airflow and monitoring CO levels (2019, pp. 36-37).
What about the effect of daily flavored coffee consumption on coffee consumers? Who knows? The FDA does not regulate diacetyl or 2,3-pentanedione because they are considered safe to eat (U.S. Department of Labor, 2010). Even though the dangers of the chemicals are from inhalation when heated, the FDA does not do testing for inhalation. What about the safety of roasterie employees? Well, OSHA does not regulate either diacetyl or 2,3-pentanedione (U.S. Department of Labor, 2010).
Rather than seeing the nonexistent regulation of alpha-diketones as a failure of regulatory agencies, we should be re-evaluating the U.S.’s approach to chemical regulation as a whole. In 1976, the U.S. grandfathered 62,000 chemicals into use with the passage of the Toxic Substances Control Act (TSCA) (Krimsky, 2017). Though the Lautenburg Chemical Safety for the 21st Century Act was passed as a reform, Krimsky notes that it has faced a number of roadblocks under the current administration (2017). The U.S. must change its chemical regulatory processes to be proactive about restricting the use of hazardous chemicals.
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Bailey, R. L., Cox‐Ganser, J. M., Duling, M. G., LeBouf, R. F., Martin, S. B., Bledsoe, T. A., Green, B. J., & Kreiss, K. (2015). Respiratory morbidity in a coffee processing workplace with sentinel obliterative bronchiolitis case. American Journal of Industrial Medicine, 58(12), 1235–1245. https://doi.org/10.1002/AJIM.22533
Centers for Disease Control and Prevention (CDC). (2013). Obliterative bronchiolitis in workers in a coffee-processing facility – Texas, 2008-2012. MMWR. Morbidity and Mortality Weekly Report, 62(16), 305–307. PubMed.
Krimsky, S. (2017). The unsteady state and inertia of chemical regulation under the US Toxic Substances Control Act. PLoS Biology, 15(12), e2002404–e2002404. PubMed. https://doi.org/10.1371/journal.pbio.2002404
R. Red Harvey, DVM, MPH, Brie H. Blackley, MS, PhD, Stephen B. Martin, Jr., PhD, PE, & Marcia L. Stanton, BS. (2019). Evaluation of exposures and repiratory health at a coffee roasting and packaging facility (No. 2016-0164–3341; Health Hazard Evaluation Program, p. 60). National Institute for Occupational Safety and Health. https://www.cdc.gov/niosh/hhe/reports/pdfs/2016-0164-3341.pdf
The National Institute for Occupational Safety and Health. (2017, October 3). Flavorings-Related Lung Disease. Centers for Disease Control and Prevention. https://www.cdc.gov/niosh/topics/flavorings/exposure.html
United States Department of Labor. (2010, October 14). Occupational Exposure to Flavoring Substances: Health Effects and Hazard Control. Occupational Safety and Health Administration. https://www.osha.gov/dts/shib/shib10142010.html
