NIOSH: Coffee Workers May Be at Risk for Lung Disease

Published January 27, 2016

A new NIOSH Science Blog post summarizes agency research indicating that workers at coffee processing facilities may be at risk for lung disease caused by occupational exposure to diacetyl and 2,3-pentanedione, volatile organic compounds that are naturally produced when coffee beans are roasted. Diacetyl and 2,3-pentanedione are also produced by chemical manufacturers to be used as ingredients in flavorings for some food products such as microwave popcorn and bakery mixes. The lung disease obliterative bronchiolitis has been previously identified in flavoring manufacturing workers and microwave popcorn workers, but physicians at a university medical center recently diagnosed the disease in five employees who had worked at a coffee processing facility.

During a health hazard evaluation, NIOSH found elevated levels of diacetyl and 2,3-pentanedione in the air of the facility where the five individuals had worked. NIOSH staff identified several sources of the chemicals, including flavoring chemicals added to roasted coffee beans in the flavoring area; grinding and packaging unflavored roasted coffee in a distinct area of the facility; and storing roasted coffee in hoppers to off-gas. Current employees displayed respiratory symptoms consistent with undiagnosed lung disease. The agency is conducting health hazard evaluations of several other coffee processing facilities to further investigate work-related exposures to diacetyl and 2,3-pentanedione.

The agency has developed a Web page for coffee processing facilities that includes interim recommendations, including air sampling to detect and measure potential concentrations of the chemicals. NIOSH has proposed a recommended exposure limit (REL) of 5 ppb for diacetyl and 9.3 ppb for 2,3-pentanedione as a time-weighted average for up to 8 hours per day during a 40-hour workweek. The agency has also proposed 15-minute short-term exposure limits (STELs) of 25 ppb for diacetyl and 31 ppb for 2,3-pentanedione. According to NIOSH, these interim recommendations may change based on additional knowledge the agency expects to gain throughout 2016.

In July, NIOSH released guidance to reduce workers’ exposures to diacetyl through engineering controls, best work practices, and techniques for monitoring airborne diacetyl exposures.

For more information, see NIOSH’s blog post.