NIOSH: Coffee Workers May Be at Risk for Lung Disease
Recent NIOSH research indicates 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 and released when coffee beans are roasted and when coffee is ground. 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, bakery mixes, and flavored coffee. The lung disease obliterative bronchiolitis, previously identified in workers in the flavoring manufacturing and microwave popcorn industries, was recently diagnosed in five employees who had worked at a coffee processing facility that roasted, ground, and flavored coffee. NIOSH found elevated levels of diacetyl and 2,3-pentanedione in the air of the facility, and current employees reported respiratory symptoms consistent with undiagnosed lung disease.
The lung disease obliterative bronchiolitis was recently diagnosed in five employees who had worked at a coffee processing facility that roasted, ground, and flavored coffee.
“When we looked at the mean 2,3-pentanedione and diacetyl personal air samples by job title, we found the concentrations were highest for employees in the flavoring room and unflavored grinding packaging room,” says Rachel L. Bailey, DO, MPH, a medical officer in the NIOSH Respiratory Health Division. Among the workers who had high exposures were the mixers, flavoring specialists, packers, and the operators of grinding and packaging machines, Bailey says. NIOSH has 11 ongoing health hazard evaluations of coffee processing facilities. Bailey notes that NIOSH staff will collect both area and personal air samples, and perform task-based air sampling during roasting, grinding, and other tasks. Workers at these facilities will also complete health questionnaires to determine whether they are experiencing respiratory symptoms. NIOSH will also administer breathing tests to assess lung function. “Many workplace interventions that we’ve recommended in the flavoring industry and the microwave popcorn industry, such as isolation, using local exhaust, general ventilation, and respiratory protection, might be useful in the coffee processing industry,” Bailey says. In July, NIOSH released guidance to reduce workers’ exposures to diacetyl and 2,3-pentanedione. The agency has also 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 (TWA) for up to 8 hours per day during a 40-hour workweek. For comparison, ACGIH’s threshold limit value (TLV) for diacetyl is two times higher than the proposed REL: 0.01 ppm TWA, or 10 ppb TWA. Because the proposed RELs are so low, NIOSH is interested in identifying and using sensors or technologies that can capture these low levels to help researchers understand peak exposures, says AIHA member Ryan F. LeBouf, PhD, CIH, a research industrial hygienist in the NIOSH Respiratory Health Division. “It’s also important to look at other techniques for sampling flavorings,” LeBouf says. “One thing we’ve been doing is using evacuated canisters to sample whole air. Instead of using a sorbent and drawing air across the sorbent, you just collect your air into a canister and take it back to the lab and analyze it. It’s a lot easier in the field, and all the onus of analysis is on the laboratory staff.” LeBouf is working on a draft method for the canisters to be published in the NIOSH Manual of Analytical Methods.
An Interview with Rachel Bailey and Ryan LeBouf: see the sidebar at the end of this article.