But most workers don't realize their lungs may be in danger from exposure to diacetyl
Tucked inside a burlap sack at room temperature, green coffee beans pose no known danger.Funnel a 90-pound batch into a 430-degree roaster and things change. A chemical reaction between the beans' sugars and amino acids creates a toxic compound capable of crippling the lungs of anyone nearby.
But few, if any, commercial coffee roasters know it.
They stand close, smelling the beans periodically during the 14 minutes it takes to turn them into a ready-to-be-ground roast. As the beans spill from the roasting drums into the cooling rack, roasters again inhale the fumes — the aromas made delicious, in part, by the same molecular formula tied to hundreds of injuries and at least five deaths.
We don't make flavored coffee, many in the roasting business say. It's not a problem for us.
But air sampling by the Milwaukee Journal Sentinel shows reason to worry.
Tests at two midsized Wisconsin roasteries that agreed to let the news organization analyze the air in their production areas found diacetyl levels from unflavored roasted coffee that exceeded safety standards proposed by the U.S. Centers for Disease Control and Prevention.
In some areas, by nearly four times the concentration.
Workers exposed to similar levels at popcorn plants suffered serious, incurable lung disease.
"If roasters our size knew what this was, they would be super proactive," said Matt Earley, co-founder of Madison-based Just Coffee Cooperative, one of the two roasting operations that allowed the air sampling. "There needs to be hyper-awareness among people roasting and grinding coffee."
It's been known for years that diacetyl destroys lungs. So why is it still harming coffee workers and allowed in e-cigarettes?
Read the original report by Milwaukee Journal Sentinel reporter Raquel Rutledge on the hazards of diacetyl and other chemicals used in the flavoring industry.
Four other roasting companies around southeastern Wisconsin — Anodyne, Colectivo, Stone Creek and Sheboygan-based Torke — declined to allow the Journal Sentinel to sample the air around their workers.
The Journal Sentinel's diacetyl testing follows the discovery of five workers in a commercial coffee roasting plant in Tyler, Texas, who contracted debilitating lung diseases linked to the chemical.
The workers — one of whom was put on the waiting list for a lung transplant — believed their illnesses were caused by diacetyl in the liquid they added to the beans at Distant Lands Coffee to make hazelnut-flavored coffee. The coffee workers filed a lawsuit against the flavoring manufacturer in 2012 and settled it in October.
Nobody paid much attention at the time to levels of naturally occurring diacetyl wafting from the beans themselves. Not coffee roasters, business owners, regulators or labor unions. Although the roasting of coffee beans has been known for years in scientific circles to emit diacetyl, few studies exist measuring the concentrations and exposure levels for coffee workers. The Journal Sentinel's analysis is among the first.
Such information is critical, scientists say, because naturally occurring diacetyl is identical in structure to the synthetic version found in flavorings and causes the same damage to the respiratory system. The human body cannot differentiate between the two.
Diacetyl, hailed for its buttery flavor, has been deemed by the U.S. Food and Drug Administration as safe to ingest in small amounts, although more than a dozen studies have shown it can be toxic when inhaled.
"It's prudent to be concerned," said Kay Kreiss, a scientist with the National Institute of Occupational, Safety and Health, the research arm of the CDC, and one of the country's leading experts on diacetyl in the workplace. "We know there is a potential problem in other coffee plants.
"This merits attention because of the seriousness of the irreversible lung disease."
It's unclear how many coffee workers might be affected, as neither the government nor industry groups keep track. The U.S. Bureau of Labor Statistics lists 658 establishments nationwide that manufacture coffee or tea as their primary business. Those companies employ nearly 20,000 people.
The figures don't list job titles and they don't include smaller roasteries that operate in cafes, such as Colectivo or Stone Creek. Nearly 600,000 workers are employed by businesses that fall into that category, listed as "snack and nonalcoholic beverage bars." More than 7,000 of them work in Wisconsin.
The roast masters at Just Coffee and Valentine Coffee said they were not aware their jobs posed any danger to their lungs.
Both businesses operate out of spacious and clean facilities with industrial exhaust systems on the roasting equipment. No haze or pungent smells linger in the air. Nothing would indicate any type of threat.
"I saw the numbers and thought, 'Holy mackerel, that's a lot more than I expected,'" said Eugene Ruenger, the industrial hygienist who conducted the sampling for the Journal Sentinel. "If under these types of circumstances we've got these concentrations, think of a sweatshop where they're roasting 100 times this amount on a continuous basis."
The testing results expose potential problems in production areas of commercial settings and are not relevant to grinding and brewing coffee at home or sipping a cup in a cafe.
The degree of exposure in an establishment depends on a variety of factors such as ventilation, number and size of batches roasted, how much coffee is ground on site and what type of equipment is used.
Grinding coffee increases the surface area and releases higher concentrations of diacetyl than roasting alone, according to the Journal Sentinel samples. The government's study of the Distant Lands plant in Texas also found some of the highest levels in the breathing zones of workers who ground coffee.
Diacetyl is a byproduct of fermentation and, aside from coffee, is formed naturally in wine, beer, cheese, yogurt and other foods.
Inhaling diacetyl has proved deadly. Diacetyl attacks and obliterates the lung's tiniest airways, causing a disease known as bronchiolitis obliterans. As the body tries to heal, scar tissue builds up and blocks the airflow. The damage is irreversible.
The chemical's danger has been documented in dozens of animal studies as well as in health examinations of more than 1,000 employees exposed in U.S. workplaces over the last 15 years.
Yet the U.S. Occupational Safety and Health Administration, tasked with overseeing safety of the nation's workforce, still does not regulate it. The agency withdrew its proposal for a workplace exposure standard in 2009, after blowback from small businesses including dairies, bakeries and other food and beverage makers. Representatives of those industries argued that the new air regulation would be too cumbersome.
Mike De Sisti
Casey Blanche, roast master at Just Coffee
Cooperative in Madison, surveys a batch of coffee to ensure it is
roasting to specifications.
Founded in 2001 by two close friends concerned that coffee farmers in Mexico were being exploited, Just Coffee now employs more than 20 workers and each year roasts more than a quarter-million pounds of organic coffee. On one end of the 16,000-square-foot building sit two commercial roasting machines — a classic 45-kilo Diedrich conduction oven with a ceramic drum, giant fan and afterburner and a slightly smaller Lorning convection roaster.
Blanche is Just Coffee's head roaster. He has been in the coffee business since 2004, when he took a job as an apprentice, roasting out of a garage in Oxford, Miss. From there, he bounced around the country to Deerfield, Fla., then Boise, Idaho, working his way up to roast master at one of Green Mountain's roasting plants in Knoxville, Tenn. He landed in Madison in 2010.
Just Coffee owners credit Blanche's keen olfactory senses for the ever-important consistency in their roasts. For Blanche, roasting coffee is an artistic expression and a challenge.
"It's like a diamond," Blanche said of the uniqueness of every variety of bean. "You have to figure out how to cut it to show off its best attributes."
Tests at two Wisconsin coffee roasteries
that agreed to let the Milwaukee Journal Sentinel analyze the air in
their production areas found diacetyl levels from unflavored roasted
coffee that exceeded safety standards proposed by the U.S. Centers for
Disease Control and Prevention – in some areas, by nearly four times the
concentration.
The National Institute of Occupational Health and Safety recommends in a draft report that workers not be exposed to diacetyl at more than 5 parts per billion over an eight-hour work shift.
The American Industrial Hygiene Association and
U.S. Occupational Safety and Health Administration suggest that employer
best practices policies aim to have fewer than 5% of workshifts exceeding occupational exposure limits.
Source: Testing completed by Industrial Hygiene System for the Milwaukee Journal Sentinel
"It's like shifting a car," he said. "I just know what I need to do to get it where I want it to go."
Blanche, 36, is passionate about the craft and envisions doing it for many years. And he's happy to be at Just Coffee, where the environment is far better than any place else he's worked. He remembers the four roasting machines in Florida, all crammed into one little room with no ventilation. The air was so thick one day that Blanche passed out.
"It was like something out of an early 1900s industrial England film," he said.
In Knoxville, Blanche ran the controls for two 240-kilo roasters, four stories tall, from a closet-like room with little air circulation. Every 10 minutes — for 12 to 16 hours a day — a sample from each batch was sent to the control room for Blanche to grind. The tiny room had a window, but it didn't open.
Comparatively, Blanche said, Just Coffee resembles a worker's paradise. He didn't think there was much to worry about in terms of his health — although he said he has been curious about frequent fatigue and the black mucus that he blows out of his nose at the end of each shift.
Blanche was distraught to learn the results of the Journal Sentinel's testing: Diacetyl in his breathing zone at Just Coffee registered at 7 parts per billion, 40% higher than government scientists consider safe.
"This is my career," he said. "I don't really have a choice. I do this, or I starve."
Blanche's co-workers on the other side of the room, grinding the coffee, had it worse. Tests results show they were exposed to more than 19 parts per billion of diacetyl — almost four times the proposed safety limit.
•••
The National Institute of Occupational Safety and Health proposes
that workers not be exposed to diacetyl at air concentrations of more
than 5 parts per billion over an eight-hour work shift. The recommendation, which is advisory only, is in draft form and expected to be finalized later this year.Scientists calculated the safety limits so that no more than one person in 1,000 will get sick when exposed at that level over a 40-hour workweek during a 45-year work life. But, they say, the 45-year figure is misleading in the context of this chemical. Many workers whose lungs have been destroyed by diacetyl suffered their injuries in a matter of months, not years or decades.
"This doesn't mean they have to work 45 years to get sick," said Christine Whittaker, chief of NIOSH's risk evaluation branch. "If exposed to higher levels, we'd expect them to get sick sooner and we'd have more cases."
That was the situation in some of the microwave popcorn plants in the early 2000s.
"We had people, who, under our eyes,...developed the disease in a four-month period," said the agency's Kreiss.
In addition, scientists say brief spikes in exposure may carry a greater risk than long-term lower levels.
"Because the risk for occupational lung disease may be partly due to short-term peak exposures, an exposure limit based on an eight-hour TWA (time weighted average) may not be sufficient to protect workers," a 2006 study of hundreds of workers at six microwave popcorn plants stated.
At one popcorn factory, quality-control workers had average exposure levels of 20 parts per billion — about the same as the coffee grinders tested by the Journal Sentinel. One in 11 had obstructed airways. A mixer at another plant, also exposed to 20 parts per billion of diacetyl, had impaired lung function.
Those findings initially surprised government scientists studying the issue. They hadn't expected a higher prevalence of lung disease among workers exposed to lower average levels.
"That really shook us up," Kreiss said. "We realized maybe it's these high peak exposures."
Among the scientists' most alarming discoveries: Nearly a quarter of the workers with abnormal lung function had no symptoms. They didn't feel short of breath, have a chronic, dry cough or experience unusual fatigue.
"It's really sad, because you don't know you have it until it's too late," said Dan Morgan, head of the respiratory toxicology group at the National Institute of Environmental Health Sciences in North Carolina.
Morgan said the dose makes the poison.
"You may have a safe level but go up just a little bit and have a toxic level," he said. "If NIOSH is recommending 5 parts per billion, I think I would be concerned with anything over that."
The American Conference of Governmental Industrial Hygienists adopted an occupational exposure limit in 2012 for diacetyl of 10 parts per billion over an eight-hour work shift and 20 parts per billion for a 15 minute short-term limit. Workers grinding coffee at Valentine Coffee were exposed to 60 parts per billion of diacetyl in a short-term sample.
David Egilman, a medical doctor and associate professor at Brown University, argues that the safe exposure limit for diacetyl should be even lower than NIOSH proposes. Egilman cites the body of scientific studies, as well as an internal analysis in 2005 by ConAgra, as evidence that the limit should be set at 1 part per billion over an eight-hour work shift.
"There's a lot we don't know. It's complicated," he said. "This is biology. It's not all linear."
Adding to the danger is the fact that another chemical compound — 2,3-pentanedione — is released during roasting and grinding coffee. Recent studies have found the chemical, a close cousin to diacetyl, is equally destructive to lungs.
Because the substances have similar toxicological effects, scientists also consider an "additive mixture formula," meaning exposure should be measured based on the combined levels.
The Journal Sentinel had the 2,3-pentanedione levels measured at both roasting plants and results showed the chemical added to overexposure levels in nearly every case.
•••
So why doesn't there appear to be an epidemic of sick coffee roasters?Epidemiologists say diacetyl-related diseases are hard to trace. Doctors don't always inquire about patients' jobs or what chemicals they might be exposed to.
Many aren't familiar with the lung diseases associated with diacetyl and misdiagnose patients with asthma or other similar ailments. Tests are not always sensitive enough to detect trouble. Workers might not have symptoms or aren't aware that their shortness of breath or cough could be related to their coffee work.
"In flavoring manufacturing plants, cases have been occurring for decades unrecognized," Kreiss said.
Clusters of workers with diminished lung capacity first surfaced in the popcorn industry in the early 2000s. Doctors and scientists connected the sicknesses and five deaths to the diacetyl used in the buttery flavor in microwave popcorn. Subsequent lawsuits prompted manufacturers to take precautions and shift away from diacetyl. To date, nearly 1,000 lawsuits have been filed, with awards and settlements totaling hundreds of millions of dollars.
In the Texas coffee cases, a pulmonologist happened to question why a man in his 30s who didn't smoke suddenly had the lung capacity of a 70-year-old. He asked where the man was employed and what chemicals he worked with. The doctor ultimately identified four more workers with the same devastating lung disease. All five had been exposed to diacetyl.
The U.S. Bureau of Labor Statistics keeps track of on-the-job injuries reported by employers, and in 2013 tallied roughly 400 injuries among coffee and tea manufacturers. But the agency doesn't list specific diseases or job titles. Critics have long argued the numbers are significantly lower than reality. Employers often overlook long-term illnesses and don't always follow reporting requirements.
In 2014, OSHA inspected 24 of the roughly 650 firms whose primary business is coffee or tea manufacturing.
Because there is no standard regarding exposure to diacetyl, OSHA has no limits to enforce. Other regulations could address diacetyl problems if inspectors were aware of the issue and looking for exposure. Records show the provisions are seldom used.
A "general duty" clause requires employers to provide a working environment that is "free from recognized hazards that are causing or likely to cause death or physical harm." Last year, just one coffee company was cited for violating that clause.
Another regulation requires employers to inform workers about hazardous chemicals they are working with and warn them of symptoms and potential long and short-term health effects of exposure. Three coffee companies were cited for violating that standard.
Standards also mandate that companies have respiratory protection plans and provide personal protective equipment when necessary. OSHA cited just two coffee companies last year for not adhering to provisions of that standard.
The agency's database doesn't specify whether any of the violations were related to diacetyl.
NIOSH scientists sounded a stark warning in 2013 after the discovery of lung disease in the Texas coffee workers.
"Because risk was not recognized previously in this industry," the authors wrote in a CDC report, "the...cases support the need for widespread hazard assessment in all industries using flavoring chemicals or generating diacetyl."
But OSHA was already aware. The agency had learned of the risk of diacetyl exposure in the coffee industry five years earlier.
In 2008, an OSHA contractor went into an undisclosed coffee roasting facility and took air samples aimed at detecting diacetyl used in flavoring the coffee. Results showed levels similar to those found in some areas of the popcorn plants.
Mike De Sisti
Industrial hygienist Eugene Ruenger, hired by the
Milwaukee Journal Sentinel to collect air samples at two coffee
roasteries in Wisconsin, affixes an air sampling tube to Benjamin
Lisser, a production worker at Just Coffee.
The researchers appeared to be stumped by that result.
"It is not possible from these results to determine the reason for this effect," the authors wrote.
In the following years, when OSHA launched programs to beef up inspections of industries that use diacetyl, no mention was made of coffee. The agency targeted more than a dozen industries — cheesemakers, peanut butter plants, wineries, cookie and cracker manufacturers.
Coffee roasteries were not included.
Although government doctors and researchers suspect coffee workers are at risk, NIOSH isn't allowed to simply go in and test the air or workers' lung functioning. The agency needs to be invited in by a company's management, a group of at least three workers, or a union.
Nobody in the coffee business has asked, Kreiss said.
Until now. Following the results of the Journal Sentinel testing, Just Coffee is seeking NIOSH's assistance in reducing exposure levels in the plant and in setting up a medical surveillance program to monitor workers' health.
The agency's experts are scheduled to visit the plant in July.
"I'm proud of the fact we're on the forefront of this," said Earley, the co-owner. "This could be something that really helps roasters understand it's something they need to pay attention to."
•••
Trade groups representing the major players in the coffee industry, as well as smaller specialty roasters, downplay any danger."It's not a large issue," Joe DeRupo, spokesman for the National Coffee Association, said in an interview. "There is a very, very small amount created naturally in the roasting of coffee ...It doesn't get into the air, so it's not a problem."
DeRupo tied the Texas coffee workers' illnesses to the synthetic flavorings and "poor plant hygiene conditions, which included improper ventilation and absence of personal protective equipment."
"There has been no proven connection between the natural roasting byproduct diacetyl and obstructive lung disease," he wrote in an email response to questions.
Mike De Sisti
Michael Cothroll monitors a roast at Valentine Coffee.
The industry's scientific advisory group monitors and analyzes studies on coffee, funds its own research and performs "health issues management to help ensure that a balanced message is presented by the media," according to the association's website.
Candace Doepker, a toxicologist for the advisory group, whose name is on the presentation regarding diacetyl, declined to be interviewed by the Journal Sentinel. She said the coffee association asked her not to speak about it.
Starbucks, the nation's largest coffee chain, did not return phone calls or emails inquiring about worker exposure to diacetyl.
Ric Rhinehart, executive director of the Specialty Coffee Association of America, said the trade group hasn't gotten "any indication" that harmful levels of diacetyl occur from roasting unflavored coffee.
Rhinehart said he had never seen studies revealing what levels of diacetyl are present when roasting unflavored coffee. He did not know of any companies that had tested the air around workers.
"People have been roasting coffee for thousands of years," he said. "Where is the matching epidemiology for it?"
The small and midsize coffee roasting companies around southeastern Wisconsin that wouldn't allow the Journal Sentinel to sample the air said they weren't aware of any problems with diacetyl from roasting unflavored coffee.
Colectivo representatives called diacetyl a "nonissue" in their business and said it's not relevant because "we operate at such a high level."
After the Journal Sentinel's inquiry, company executives posted a statement on their website recapping what management had told workers regarding diacetyl.
"This substance occurs naturally in many foods and beverages — Chardonnay, beer, coffee, butter and cream all have diacetyl in them. This substance is developed during fermentation processes," wrote Lincoln Fowler, co-founder of Colectivo. "People consume this product daily and have been for centuries.
However, artificially synthesized diacetyl can create very high concentrations in the air people breathe, which may be unsafe.
"We have ensured that there is no artificial diacetyl in our work environments, nor has there ever been to our knowledge."
The statement assures workers that the company will "re-examine our work environments and ensure they exceed the standards that exist."
•••
The owners of Valentine Coffee on Milwaukee's west side said they
knew about diacetyl, but only in the context of wine and other alcohol.Robb Kashevarof and Joe Gilsdorf had worked in the wine and beer businesses before pursuing coffee roasting. To them, diacetyl was a flavor that would affect the taste of a Chardonnay, an ale or a lager.
When the pair moved their coffee roasting business into the building on W. Vliet St. in 2012, they spent an extra $40,000 on a catalytic oxidizer to limit the pollution spewing into the outside air.
Like Just Coffee in Madison, they now have two commercial roasters and grinding going on in one large room. Sliding glass doors divide the roasting and grinding area from a small tasting room, where baristas specialize in making pour-overs for the public.
On a weekday in April, air samples taken from the breathing zones of an employee grinding and packaging roasted coffee found 20 parts per billion of diacetyl in the air and nearly 30 parts per billion of 2,3-pentanedione.
Levels of diacetyl around the head roaster, Michael Cothroll, were about the same those for his counterpart at Just Coffee. Concentrations exceeded the government's draft recommendation by 40%, registering at slightly more than 7 parts per billion.
"I think about my health," Cothroll said. "I wear ear protection. I pay attention to how I'm lifting the 45-pound bags."
He hadn't known his lungs were at risk.