Coffee Workers Exposed to Dangers of Diacetyl

A new Center for Disease Control study uncovers the danger of exposure to diacetyl by various workers at coffee processing plants.  Studies reveal that diacetyl occurs naturally in coffee roasting even without flavoring and dangerous fumes from diacetyl coffee are released in greater quantities during the grinding process.

Diacetyl (2,3-butanedione) and acetyl prpionyl (2,3-pentanedione) have been blamed for hundreds of lung injuries and many deaths in the popcorn and flavoring industry.  Diacetyl and acetyl proprionyl are volatile organic compounds (VOCs) known as alpha-diketonoes that are added as ingredients in food flavorings and used in some food products such as microwave popcorn, bakery mixes, and flavored coffee.  It now appears that non-flavored coffee workers are at similar risk since diacetyl occurs naturally in coffee.

Diacetyl Coffee

The August 2017 Health Hazard Evaluation Report has been released with recommendations on steps coffee roasting facilities can take to protect their workers.  In addition, a medical monitoring program should be established to protect employees who work in the production area.  Early identification of symptoms from inhalation of diacetyl is imperative in protecting workers.

Suspicions about work-related lung injuries occurring in the coffee industry are not new.  In 2013, the CDC identified workers in a coffee-processing facility in Texas who experienced progressive shortness of breath that was not properly diagnosed with a diagnosis of work-related obliterative bronchitis.  Early diagnosis with the flavoring-related lung disease at the Texas plant may have prevented others from getting sick and could have helped in the treatment of these two coffee workers. 

The two cases of bronchiolitis obliterans identified in 2013 at the coffee-processing facility suggested the expansion of the number of workers potentially at risk for the flavoring-chemical related disease.   

Health Hazards Of Exposure To Diacetyl

In November 2015, the National Institute for Occupational Safety and Health (NIOSH, which is the research arm of the CDC) followed the CDC identification of these two coffee-plant workers with an article and a dedicated website about the health hazards of exposure to diacetyl at a coffee processing plant.  In addition, NIOSH published standards and recommendations to prevent exposure at coffee processing plants and called for additional research into how coffee roasting, grinding, and storage could negatively affect the health of coffee production workers. 

NIOSH followed their 2015 recommendations with further visits to coffee roasting plants in 2015 and 2016 as noted in the August 2017 Health Hazard Evaluation Report.  During visits to a Wisconsin coffee roasting facility at two separate times, researchers collected air samples and sampled coffee beans to measure the real-time air levels of diacetyl.  They also administered health questionnaires and performed breathing tests with several of the coffee-plant employees. 

This further research found that coffee plant workers were four times more likely to report respiratory symptoms than the normal U.S. population.  Eye, nose, and sinus symptoms were the most commonly reported symptoms.  Wheezing was the most common lower respiratory symptom.