Coffee Roasting Lung Risks Examined by CDC

Increasing evidence continues to suggest that more than 600,000 employees working in coffee shops and coffee manufacturing plants throughout the U.S. may face a risk of serious and potentially fatal lung problems due to chemicals released by grinding coffee beans. 

According to a press release issued on April 6, the U.S. Centers for Disease Control and Prevention (CDC) and the National Institute of Occupational Safety and Health (NIOSH) are testing for employee exposure levels to diacetyl and 2,3 pentanedione at about a dozen coffee processing plants nationwide.

The two chemicals are used to add buttery flavoring to foods and beverages, but have also been tied to the deadly lung disease known as bronchiolitis obliterans, more commonly known as “popcorn lung”, since it has been commonly diagnosed among individuals working in microwave popcorn manufacturing facilities.

The CDC and NIOSH initiated their research after the Milwaukee Journal Sentinel released the results of an independent investigation, which highlighted how naturally occurring chemicals released during the grounding of coffee beans may expose workers to the synthetic additives.

Research has found roasting coffee beans naturally releases chemicals known as diacetyl and 2,3-pentanedione, both of which have been linked to the development of popcorn lung among microwave popcorn workers. The chemicals belong to a class of volatile organic compounds known as alpha-diketones, and were used to provide butter flavoring to microwave popcorn in prior years.

Referred to interchangeably as bronchiolitis obliterans, obliterative bronchiolitis or popcorn lung, the condition is characterized by the scarring and inflammation of small airways that lead to diminished lung capacity and breathing problems. The disease is irreversible and severe cases may require lung transplants or lead to death.

Currently, the CDC prohibits workers from being exposed to more than 5 parts per billion of diacetyl over an eight-hour work day during a 40-hour workweek. However, an industrial hygienist who tested the air in two roasting facilities found levels of diacetyl and 2,3 pentanedione at up to four times the allowable limit.

The CDC and NIOSH were contacted by Madison, Wisconsin-based company Just Coffee, who requested a full health hazard evaluation and to specifically test for chemicals linked to popcorn lung disease. The CDC and NIOSH visited the facility in July 2015, and spent several days taking air samples to measure the concentration levels of diacetyl and 2,3 pentanedione as well as evaluating the building ventilation and operating systems.

Three of the air samples taken at the facility contained levels of the two chemicals surpassing the legal amount set by the CDC.

According to the CDC, the diacetyl levels were recorded at 7 parts per billion which is 2 parts per billion over the allowable limit. However, the NIOSH researchers returned to the facility recently to take additional samples during the winter months when the facilities large bay doors and windows were not open during production and allowing additional ventilation. The results from the additional tests are still pending.

Worker Safety Concerns

The CDC and NIOSH are concerned that more than 600,000 employees across the U.S. working in coffee shops, facilities, and production plants may be exposed to the risk of lung disease without any knowledge or warning from their employer.

Scientists at the NIOSH research facility are warning employees to never stick their heads in, or hover over, bins where coffee grounds are kept, as tests have shown levels of diacetyl reach upward of 7,000 parts per billion. Exposure to such high levels could cause serious and even fatal adverse reactions.

The CDC first warned about the potential popcorn lung risk for coffee workers in October 2015.

NIOSH and the CDC are stressing the importance for coffee shop owners and facilities to take the exposure threats serious and have the facilities tested by a professional company due to the inability to smell or see the air pollutants. The agencies are also asking employers to implement medical surveillance programs that would monitor employee lung function and be able to detect early signs of bronchiolitis obliterans from diacetyl exposure.

Coffee workers with concerns about potential exposure to diacetyl or 2,3 pentanedione should consult with their doctors immediately to be evaluated for early signs of bronchiolitis obliterans. However, without severe symptoms of scarring and inflammation of the small airways leading to diminished lung capacity and breathing problems, doctors often misdiagnose the condition as asthma, chronic bronchitis, emphysema, or pneumonia. It is important for those who are evaluated to disclose to their doctor that they work in a coffee roasting facility and could be exposed to harmful chemicals.

More than 300 popcorn lung lawsuits have been filed in recent years, with most of those coming from employees of popcorn manufacturers. However, some heavy consumers of popcorn have also been diagnosed with the lung disease and have filed lawsuits against companies that manufactured or used the flavoring.

The CDC warning about the potential link between coffee and popcorn lungs does not indicate whether there is any risk to those who roast coffee beans regularly at home.