DAVID GREENE, HOST:
We've known for a while about this chemical that caused lung disease in workers at a microwave-popcorn factory. Well, now it looks like that same chemical could affect the coffee world. Not people at home grinding or brewing up a pot, but people who make a living in roasting and packaging coffee. Susan Bence from member station WUWM reports.
SUSAN BENCE, BYLINE: Step into Mike Moon's Madison, Wis., coffee-roasting world, and the aroma of beans from Brazil to Laos immediately washes over you. Moon says he aims to run an efficient and very safe plant. That starts the minute beans spill out of the roaster.
MIKE MOON: Now, the cooling can is designed so that it draws air from the room in over the beans and exhausts that air out of the facility. So it's really grabbing a lot of all of the gases that are coming off of the coffee.
BENCE: So why are these gases so worrisome? Because of diacetyl, a natural byproduct of the coffee-roasting process. Diacetyl is used commercially and is added to foods like microwave popcorn to help with the flavor. But exposure to diacetyl can be hard on the lungs, as Rachel Bailey observed four years ago at a coffee-roasting business in Texas. She is with the CDC's National Institute for Occupational Safety and Health, or NIOSH.
RACHEL BAILEY: Physicians at a nearby university medical center had diagnosed five former workers with a very severe lung disease called obliterative bronchiolitis. So we visited this facility...
BENCE: What they found was diacetyl.
BAILEY: ...And we found the highest concentrations in the flavoring room and then in the grinding-packaging room.
BENCE: As researchers still try to figure out how much exposure is too much, Bailey worries about the potential exposure of thousands of people nationwide involved in the coffee business, from roasting to packaging. But in Madison, Wis., Mike Moon says he knew nothing about the chemical. But that changed when a reporter at the Milwaukee Journal Sentinel asked Moon to allow an industrial hygienist to check for the presence of diacetyl. The results raised concerns, and Moon immediately asked NIOSH to dig deeper. He's waiting for a final report. For now, Moon is following NIOSH's advice.
MOON: We're circulating the air in the facility more, we're exhausting air - being more deliberate about that - and bringing in fresh air.
BENCE: NIOSH is juggling a dozen requests from roasters around the country. None report diacetyl-related health problems by its employees. Meanwhile the National Coffee Association's Joe DeRupo says his group is carrying out its own analysis.
JOE DERUPO: We are looking further because current science does not indicate any support for the premise that exposure to diacetyl alone, that's created naturally in the roasting and grinding of unflavored coffee, increases the risk of obstructive lung disease.
BENCE: In Milwaukee, coffee-roaster Lincoln Fowler established some best practices that appear to be working. He spent years perfecting his shop's airflow system and recently called in experts to test it. The diacetyl count there came in well below NIOSH's proposed standards. Fowler thinks concerns about workplace well-being should be put in perspective.
LINCOLN FOWLER: Our 154-pound bags of coffee - I'm constantly after our staff to be careful how you lift, and I would argue that potential back problems are probably a much more significant threat.
BENCE: People eager for official guidance on safe diacetyl levels will have to wait. Although NIOSH developed recommendations for safe exposure, rules are not yet established. For NPR News, I'm Susan Bence in Milwaukee.
GREENE: You're not going to want to miss All Things Considered later today because your childhood dreams are going to come true. "The Jungle Book" is coming to life in a new movie.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.