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Coffee Roasting and Packaging Facilities

Occupational asthma was thought to be the main respiratory risk for workers in coffee processing facilities. Previous studies identified green and roasted coffee bean dusts and castor bean dusts from contaminated shipping bags as asthmagens (Figley and Rawling 1950; Karr et al. 1978; Zuskin et al. 1979, 1985; Thomas et al. 1991). Asthmagens are substances that can cause asthma. In 2013, obliterative bronchiolitis was reported in former workers of a coffee roasting and packaging facility that roasted, ground, and flavored coffee (CDC 2013).

Main Points

  • Obliterative bronchiolitis, an irreversible lung disease, was previously identified in flavoring manufacturing workers and microwave popcorn workers who worked with diacetyl (2,3-butanedione) or butter flavorings containing diacetyl.
  • Workers at coffee processing facilities can be at risk. NIOSH investigators published a paper in the American Journal of Industrial Medicine about a health hazard evaluation at a coffee processing facility that had five former workers with obliterative bronchiolitis (Bailey et al. 2015).
  • Diacetyl and 2,3-pentanedione, a chemical similar to diacetyl, are volatile organic compounds known as alpha-diketones. These chemicals can be manufactured to make different flavorings that are sometimes added to food products.
  • Diacetyl and 2,3-pentanedione are also naturally produced and released during the coffee roasting process (Daglia et al. 2007). Grinding roasted coffee beans produces greater surface area for the off-gassing of these and other chemicals (Akiyama et al. 2003).
  • NIOSH has published recommended exposure limits (RELs) for diacetyl and 2,3-pentanedione in workplace air (NIOSH 2016-111). If elevated levels of diacetyl (2,3-butanedione) or 2,3-pentanedione are detected in workplace air, workplace interventions should be put in place to reduce the levels. The effectiveness of these interventions (e.g., engineering controls, administrative changes) should be verified by follow-up air sampling. NIOSH has published a best practices document that describes work interventions and exposure monitoring for occupational exposures to diacetyl and 2,3-pentanedione (NIOSH 2015).
  • Employees may need to wear appropriate fit-tested respirators until workplace interventions can be put in place to reduce air levels of diacetyl and/or 2,3-pentanedione. These respirators should protect against organic vapors and particulates. A medical surveillance program that includes health questionnaires and breathing tests (e.g., spirometry) also may be indicated to screen for respiratory symptoms or abnormalities in employees.
  • NIOSH is working with a number of coffee processing facilities through the Health Hazard Evaluation Program.