Chemicals From Roasting Coffee May Be Cramping Lungs
Maybe you should start calling it “coughee.” Because it’s possible that the people roasting those delicious black beans for your morning cup are being exposed to dangerous levels of volatile chemicals—ones that are linked to a delightful-sounding condition called obliterative bronchiolitis.
The most recent alarm comes comes from investigative journalists at the Milwaukee Sentinel-Journal, who outfitted workers at two boutique roasters with air sensors, and picked up elevated levels of diacetyl, a dangerous volatile. Now that it could be hitting those additive-averse artisanal roasters gentrifying former industrial nooks, the real question is whether long bushy hipster beards work as air filters.
OK seriously, the real question is whether roasting non-flavored coffee poses any real risk to workers. The Sentinel-Journal study picked up diacetyl quantities up to four times higher than the CDC’s tentative recommended limit. And in 2013, the CDC itself released a pair of case studies that showed strong evidence that people had developed obliterative bronchiolitis after roasting for just a few months.
“You have a wind pipe and it divides into two, and then keeps branching two by two until eventually you get down to the last few branches,” says Marshall Hertz, a physician and pulmonary specialist at University of Minnesota Health. “Those little twigs right before you get to the air sacs are called bronchiole.” When something blocks or scars those twigs, the air sac on the other side can’t inflate. Each blocked air sac represents a fraction less air that lung is capable of breathing—breathing capacity it does not get back. Hence the obliterative part.
Diacetyl is a chemical culprit that causes certain types of obliterative bronchiolitis. “These particles are small enough that they bypass hairs and mucous in the nose and throat and get into those very smallest airway passages,” says Alan Barker, a pulmonary specialist at Oregon Health and Science University. “There has been a suggestive study done of coffee roasting workers, compared to people who had desk jobs in coffee plants,” says Barker. “And they showed that the roasters had more things like cough and shortness of breath than those who were not closely exposed.”
In August, the National Institute of Occupational Safety and Health—the CDC’s workplace hazards group—released a draft rule recommending that no worker should breathing air that is 5 parts per billion diacetyl over the course of a forty hour work week. They break it down even further by saying that workers should not breathe in levels above 25 parts per billion for any 15 minute span.
This isn’t diacetyl’s first time in the food safety spotlight. Nineties kids may remember it as the main ingredient that gave buttery flavor to the crap they used to drizzle on popcorn. A 2002 paper by CDC researchers revealed popcorn factory workers were getting obliterative bronchiolitis from all the diacetyl they were breathing in. The CDC even gave this food processing version of the illness its own unique brand: Flavorings-related lung disease.
Beer brewing also emits diacetyl, as does wine making, as do numerous other food-making processes. And scientists have found that the process of making flavored coffees—like the bags of bags of Dunkin Donuts Hazelnut Blend your nonna in Connecticut sends you in your annual December care package—also let off dangerous levels of diacetyl. But most popcorn, beer, wine, and flavored coffee producers now try to protect their workers by providing air masks, improved ventilation, or removing the additive altogether.
But the diacetyl in those non flavored (organic, fair trade, gluten-free, vegan, and humanely crapped out by a civet) beans is naturally-occurring. Something that some roasters might not even be aware of. “No, I haven’t heard about any of that,” said Eileen Rinaldi, owner of Ritual Coffee Roasters in San Francisco.
And maybe she doesn’t need to hear about it. America’s biggest coffee trade group says there’s scant evidence that natural beans are roasting out diacetyly at dangerous levels. “It’s a very volatile compound, in that it dissipates very quickly,” says Joseph DeRupo, a spokesman for the National Coffee Association. “And most of the roasting apparatus is made to minimize any exposure risk to the workers.” He points to closed exhaust systems coming up from the roasting stacks, and cooling trays that draw air down and away from the workers.
But those are for large, industrial scale roasters. What about the entrepreneurial hipsters roasting beans on a vintage Probat in their industrial loft space? DeRupo recommends they check out OSHA regulation 3143 on industrial hygiene and invest in some protective gear and proper ventilation. Also of help, the CDC’s workplace research branch has offered to come check out any roaster who wants to volunteer for an inspection.
DeRupo also also points out that the Journal-Sentinel‘s study wasn’t peer reviewed and only looked at two roasteries in one city. Even the CDC’s pair of case studies are a lot closer being to anecdotes than evidence. And researchers agree that the current data isn’t strong enough to make a solid epidemioligical link. “I have not yet seen a conclusive slam dunk, like with the popcorn workers,” says Barker. He’s not counting out that there could be a danger, but says further studies would have to factor in cigarette smokers, ventilation systems, and individual pulmonary tests for the workers.
It will take even more studies to find out if your morning waft of coffee really is the best part of waking up.