Diacetyl and 2,3-pentanedione are alpha-diketones that are generated during the coffee
roasting process and have been shown to be related to respiratory symptoms, abnormal lung
function, and in rare cases, an irreversible disease called obliterative bronchiolitis. This study
measured personal exposures in a coffee roastery in New Zealand using a novel method
involving thermal desorption tubes, and explored the prevalence of respiratory symptoms with
a health questionnaire.
Exposures from task samples were highest for grinding (GM: 22.5 ppb diacetyl; GM: 19.3
ppb 2,3-pentanedione), followed by packaging (GM: 10.8 ppb diacetyl; GM: 9.3 ppb
2,3-pentanedione) and then roasting (GM: 4.7 ppb diacetyl; GM: 4.1 ppb diacetyl). 8h-TWA
diacetyl exposures exceeded the NIOSH REL of 5 ppb for Roaster/Packager (GM: 6.6 ppb)
and Grinder (GM: 5.3 ppb). 8h-TWA concentrations were below the NIOSH REL of 9.3 ppb for
2,3-pentanedione (Roaster/Packager, GM: 5.7 ppb; Grinder, GM: 4.6 ppb). Workers reported
nose, eye symptoms and systemic symptoms (flu-like illness or achy joints, fever or chills, or
unusual tiredness or fatigue).
This study is believed to be the first to measure personal exposure to alpha-diketones in New
Zealand coffee processing workers. Exposure to diacetyl and 2,3-pentanedione is a potential
occupational health hazard that the New Zealand coffee processing industry should be made
aware of. Further research into alpha-diketone exposure and health effects, and control
measures to minimise risks to health are recommended.