The CDC Releases Report On The Health Risks At Cof...

The CDC Releases Report On The Health Risks At Coffee Roasteries

Last year, we reported on the potential dangers of inhaling roast exhaust, specifically as it relates to a higher likelihood of developing lung disease. This was based on research being compiled by the Center for Disease Control and Prevention, and now they have released the full 67-page report, according to USA Today.

As previously noted in our first article on the topic, the main culprit suspected of causing the lung damage is a chemical called diacetyl, a naturally occurring byproduct of coffee roasting. Per the USA Today article, 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 work day… calculated to limit the risk so that no more than 1 in 1,000 workers would be expected to have reduced lung function at those exposure levels over a 45-year work life.”

When testing 49 air samples from around Just Coffee Cooperative’s 16,000-square-foot roasting facility in Madison, Wisconsin—the site where all the collection data occurred—the CDC found 10 samples that exceeded the 5 ppb threshold. From the report, “grinding roasted coffee beans, blending roasted coffee beans by hand, and weighing and packaging roasted coffee were associated with higher diacetyl levels, likely due to the close proximity of the employee’s breathing zone to the roasted beans.” Grinding coffee was tagged with the highest diacetyl exposure levels for employees at 37.6 ppb over a 14-minute time period. The report also notes that the inside roasted coffee storage bins had instances of diacetyl at 99.4 ppb but are not reflective of employee exposure.

The results of this exposure on the workers is not insignificant:

Our findings of upper-respiratory symptoms with a work-related pattern in many employees, four-fold excess of wheeze and abnormalities on lung function testing in about a third of participants suggest a burden of respiratory problems in this workforce.

CDC recommendations for means of reducing exposure to diacetyl include vacuuming instead of sweeping, which just kicks dust around; the use of masks/respirators during higher-exposure tasks; adding exhaust fans over grinding and blending stations; and the use of automated blending devices.

This report is just the first step the CDC is taking to better understand exposure at coffee roasteries. According to USA Today, they are currently doing similar research at 18 roasters across the United States, with results expected in the coming months.

The full report can be found here. To read a statement from Just Coffee regarding the findings, visit their official website.

Comments are open. Sound off below.

Zac Cadwalader is the news editor at Sprudge Media Network.



  1. Demeke

    28 September

    I think roasting also a causes for back pain as roasters spent a segnificant time bending while they roast and pick defective beans. Is there such finding too?

  2. Cameron Heath

    28 September

    This was super informative, for sure going to look into how we can improve our roastery based on this study.
    But with that said, I’m wondering how this transfers over to people cupping coffees on a regular basis?

  3. Matt Earley

    28 September

    Hi There,

    Matt EarIey from Just Coffee Co-op here. Thanks for putting this out there.

    I want to correct/clarify some of the info in your article as the science is easy to confuse. The 5 ppb that you specify as NIOSH’s upper limit for exposure is correct– the is for long-term exposures and it is how NIOSH gauges how high a risk is to employee over time. It represents an average low-risk exposure to an employee working exposed at that level for a 40 hour week over 45 years. With this metric the highest exposure level NIOSH measured at Just Coffee was 8.4 ppb. In the article you list this 5 ppb long-term exposure level and then mention that our highest detected level of alpha-diketones was 37.4 ppb. This is a 14 minute short-term exposure level and cannot be directly correlated to the NIOSH desired level of 5 ppb you mention– it is apples and oranges (long-term average vs. short-term real number).

    At any rate, thanks for keeping this issue front and center. Even though our numbers put us at low risk, we are still putting NIOSH’s remediation recommendations in place so that we can be in a “no risk” situation. All of it is quite manageable and we encourage other roasters to get their places tested.



  4. Justin Evidon

    28 September

    Why does Sprudge not open the comments section on content more often? There is a lot of content created on this site that would spark an interesting and valuable dialogue within the coffee community, and yet rarely do we have the opportunity to share our thoughts. I can understand skipping it for shop build-outs, but you’ve got interesting topics like the Lantinx coffee scene in Arizona or California considering labeling coffee as causing cancer.

  5. Brady

    28 September

    I’m curious whether or not these risks crossover to the cafe environment, especially connected with grinding coffee. The cafe I work in has hardwood and tile floors and is exclusively swept & mopped as opposed to vacuumed. All of the grinding takes place in a small area, as much as 30-50lbs of coffee in a day. I’m not sure how that compares to a roastery.

  6. dwest

    28 September

    I’ll take my chances. Coffee is worth the “risk.” However, I may start wearing a dust mask when I roast…..