Environmental characterization of a coffee processing workplace with obliterative bronchiolitis in former workers

Abstract

Obliterative bronchiolitis in five former coffee processing employees at a single workplace prompted an exposure study of current workers. Exposure characterization was performed by observing processes, assessing the ventilation system and pressure relationships, analyzing headspace of flavoring samples, and collecting and analyzing personal breathing zone and area air samples for diacetyl and 2,3-pentanedione vapors and total inhalable dust by work area and job title. Mean airborne concentrations were calculated using the minimum variance unbiased estimator of the arithmetic mean. Workers in the grinding/packaging area for unflavored coffee had the highest mean diacetyl exposures, with personal concentrations averaging 93 parts per billion (ppb). This area was under positive pressure with respect to flavored coffee production (mean personal diacetyl levels of 80 ppb). The 2,3-pentanedione exposures were highest in the flavoring room with mean personal exposures of 122 ppb, followed by exposures in the unflavored coffee grinding/packaging area (53 ppb). Peak 15-min airborne concentrations of 14,300 ppb diacetyl and 13,800 ppb 2,3-pentanedione were measured at a small open hatch in the lid of a hopper containing ground unflavored coffee on the mezzanine over the grinding/packaging area. Three out of the four bulk coffee flavorings tested had at least a factor of two higher 2,3-pentanedione than diacetyl headspace measurements. At a coffee processing facility producing both unflavored and flavored coffee, we found the grinding and packaging of unflavored coffee generate simultaneous exposures to diacetyl and 2,3-pentanedione that were well in excess of the NIOSH proposed RELs and similar in magnitude to those in the areas using a flavoring substitute for diacetyl. These findings require physicians to be alert for obliterative bronchiolitis and employers, government, and public health consultants to assess the similarities and differences across the industry to motivate preventive intervention where indicated by exposures above the proposed RELs for diacetyl and 2,3-pentanedione.

Health hazard evaluation report: evaluation of exposures and respiratory health at a coffee processing facility.

“…Occupational exposure to diacetyl and 2,3-pentanedione can cause loss of lung function and the lung disease obliterative bronchiolitis [NIOSH 2016]. Some coffee processing employees developed obliterative bronchiolitis while working at a coffee processing facility that used flavorings and had elevated levels of diacetyl and 2,3-pentanedione throughout the facility [CDC 2013;Bailey et al 2015;Duling et al 2016]. Whether coffee processing employees at other facilities are at risk of lung disease from exposures to diacetyl, 2,3-pentanedione, and 2,3-hexanedione is not known.…”

“…Diacetyl, 2,3-pentanedione, other VOCs, and gases such as carbon monoxide (CO) and carbon dioxide (CO 2 ) are naturally produced and released during the coffee roasting process [Duling et al 2016;Raffel and Thompson 2013;Daglia et al 2007;Nishimura et al 2003;Newton 2002]. Grinding roasted coffee beans produces a greater surface area for off-gassing (sometimes called degassing) of these compounds [Akiyama et al 2003].…”

“…A NIOSH health hazard evaluation at that facility demonstrated elevated levels of diacetyl and 2,3-pentanedione throughout the facility and exposure-related adverse respiratory health effects in the current workforce [Duling et al 2016;Bailey et al 2015]. Based on these findings, the coffee processing company that is the subject of this report wanted to be proactive, and thus management submitted a health hazard evaluation request to NIOSH to characterize potential exposures and perform a ventilation assessment; the management also agreed to a health evaluation.…”

Health hazard evaluation report: evaluation of exposures and respiratory health at a coffee roasting and packaging facility.

“…It has also been identified in employees at a coffee processing facility that produced unflavored and flavored coffee [CDC 2013]. A NIOSH health hazard evaluation at that facility found diacetyl and 2,3-pentanedione concentrations in the air that were concerning and identified three sources: 1) flavoring chemicals added to roasted coffee beans in the flavoring area; 2) grinding unflavored roasted coffee beans and packaging unflavored ground and whole bean roasted coffee in a distinct area of the facility, and 3) storing roasted coffee in hoppers, on a mezzanine above the grinding/packaging process, to off-gas [Duling et al 2016]. At the time of the health hazard evaluation, workers had excess shortness of breath and obstruction on spirometry, both consistent with undiagnosed lung disease.…”

Health hazard evaluation report: evaluation of exposures and respiratory health at a coffee roasting and packaging facility and attached retail cafe.

“…It has also been identified in employees at a coffee processing facility that produced unflavored and flavored coffee [CDC 2013b]. A NIOSH health hazard evaluation at that facility found diacetyl and 2,3-pentanedione concentrations in the air that were concerning and identified three sources: 1) flavoring chemicals added to roasted coffee beans in the flavoring area; 2) grinding unflavored roasted coffee beans and packaging unflavored ground and whole bean roasted coffee in a distinct area of the facility, and 3) storing roasted coffee in hoppers, on a mezzanine above the grinding/packaging process, to off-gas [Duling et al 2016]. At the time of the health hazard evaluation, workers had excess shortness of breath and obstruction on spirometry, both consistent with undiagnosed lung disease.…”