Coffee roasters may risk respiratory illness

CDC researchers recommend workers’ health be monitored

The U.S. Centers for Disease Control and Prevention has uncovered more evidence pointing to the need for people who spend their days roasting, grinding and packaging coffee at commercial plants or corner cafes to pay close attention to their health.

Researchers found workers at a midsize roastery in Wisconsin had wheezing in their chests at four times the rate expected when compared with the U.S. population with similar demographic characteristics, a new report shows.

Calling the findings statistically significant, the authors wrote, “We recommend a medical monitoring program to identify any employees who may be developing lung disease.”

The warning applies to all production workers involved with tasks such as roasting, opening bins and scooping beans, grinding, weighing and packaging coffee. It does not speak to those who grind and brew a cup or two of coffee at home each morning.

Workers told researchers they also experienced sinus and other mucous membrane symptoms that they suspected were a reaction to green coffee dust, chaff and roasted coffee dust.

In addition, more than onethird of the 16 workers screened had abnormal breathing tests, according to the study, published last month.

The report reveals for the first time the government’s medical surveillance results from employees in a coffee production facility that does not add flavors to its coffees.

Previous studies have linked added flavorings to serious lung disease. The suspected culprits? Two volatile organic compounds: diacetyl and 2, 3-pentanedione.

Diacetyl was blamed in hundreds of injuries and at least a handful of deaths in the microwave-popcorn industry in the early 2000s. It is created synthetically to instill a buttery flavor to all kinds of foods and beverages, including flavored coffee. And though the federal Food and Drug Administration has approved its use for ingestion in trace amounts, inhalation of the chemical is known to destroy lungs.

But what many in the coffee industry didn’t know until recently — after a 2015 investigation by the Milwaukee Journal Sentinel — was that diacetyl also occurs naturally from roasting coffee. And it’s released in greater quantities during the grinding process.

The National Institutes of Safety and Health recommends workers not be exposed to more than 5 parts per billion of diacetyl as a time-weighted average over an eight-hour workday. That includes both synthetic and naturally occurring diacetyl.

The CDC’s study found 10 of 49 air samples collected from the personal breathing zones of the employees at the Wisconsin roastery exceeded the recommended diacetyl level.

Matt Earley, co-founder of Just Coffee Cooperative in Madison, where the research was done, said the cooperative already has implemented engineering controls and taken other measures to help mitigate the risk since the agency was there in March 2016.

Just Coffee was one of two processors that in 2015 allowed the Journal Sentinel to test the air for diacetyl and its molecular cousin 2,3-pentandione. After the Journal Sentinel’s results found elevated levels, Earley and his business partner decided to have the CDC come in to verify the findings and help the company make improvements.

“What a great investment: to give employees peace of mind knowing they are in a safe work environment,” Earley said.

The CDC recommended Just Coffee use a vacuum instead of sweeping; provide mask and respirators for workers doing specific tasks; improve ventilation by installing local exhaust over grinders, blenders and packagers; and keep a large overhead exhaust fan operating continuously, among other measures.

The Just Coffee facility is located in a 16,000-square-foot building. The building is open and airy, and the dangers of diacetyl and 2,3 pentandione were not obvious.

And while the CDC’s findings suggested workers’ upper respiratory symptoms were work-related, determining whether the lower symptoms such as wheezing were a result of the workplace environment is more difficult.

The CDC is completing research at more than a dozen coffee facilities around the country.

Workers also experienced sinus and other symptoms that they suspected were a reaction to green coffee dust, chaff and roasted coffee dust.

JOURNAL SENTINEL MIKE DE SISTI, MILWAUKEE Casey Blanche, former roast master at Just Coffee Cooperative in Madison, Wis., surveys a batch of coffee to ensure it is roasting to specifications.