by Brianna Crandall — February 10, 2016—Obliterative bronchiolitis, an irreversible form of lung disease in which scarring blocks the movement of air, was previously identified in flavoring manufacturing workers and microwave popcorn workers who were occupationally exposed to diacetyl (2,3-butanedione) or butter flavorings containing diacetyl. Now, research finds that workers at coffee processing facilities may also be at risk, according to a NIOSH blog.
Diacetyl and 2,3-pentanedione (a diacetyl substitute) are volatile organic compounds (VOCs) produced commercially by chemical manufacturers as ingredients in flavorings that are added to some food products (e.g., microwave popcorn, bakery mixes, flavored coffee), explains NIOSH. They are also naturally produced when coffee beans are roasted. Grinding roasted coffee beans produces greater surface area for the off-gassing of these and other chemicals, contributing to worker exposures.
Physicians at a university medical center diagnosed obliterative bronchiolitis in five individuals who had worked at a coffee processing facility. NIOSH has ongoing health hazard evaluations at a number of facilities and has developed a Coffee Processing Facilities Web page with interim recommendations that may change to reflect additional knowledge.
Current recommendations include air sampling to detect and measure potential concentrations of the chemicals, and NIOSH has proposed recommended exposure limits. In addition to TWA and STEL samples, NIOSH suggests air sampling during specific processing tasks as an important way to identify where exposures may occur and for targeting workplace interventions (e.g., engineering controls, ventilation changes) to reduce contaminant air concentrations.
Employees may need to wear appropriate fit-tested respirators until these workplace interventions have been put into place and shown to reduce air concentrations in follow-up air sampling. Additionally, a medical surveillance program that includes health questionnaires and breathing tests (e.g., spirometry) may be indicated.
NIOSH says the confirmed cases reinforce the need for evaluating work-related exposures in all industries in which workers are exposed to diacetyl or 2,3-pentanedione. Although there are currently no specific federal regulations, NIOSH has drafted a recommended standard for occupational exposure that includes recommended exposure limits (RELs) for diacetyl and 2.3-pentanedione.
If exposure to diacetyl and 2,3-pentanedione are a concern in a specific workplace, contact NIOSH through the Health Hazard Evaluation Program. When situations arise that are not already understood based on prior health hazard evaluations, site visits are often conducted that can include exposure and / or health evaluations to better understand potential hazards.
For action points at affected workplaces, Best Practices: Engineering Controls, Work Practices, and Exposure Monitoring for Occupational Exposures to Diacetyl and 2,3-Pentanedione (DHHS [NIOSH] Publication Number 2015-197, published July 2015) is available from NIOSH.
