MBAA Global Emerging Issues (GEI) Committee Member Report

Ray Klimovitz, former MBAA Technical Director

As a member of the GEI Committee I have been asked to follow the consumer awareness of the effects of inhalation of elevated levels of vaporized diacetyl over time and how this could possibly affect the brewing industry2. This phenomenon is referred to as “popcorn lung” in the press. I was asked by Fred Scheer, GEI Committee chair, to prepare a report on this issue for discussion at World Brewing Congress 2008. There is no issue with inhalation of diacetyl within the brewing industry. Diacetyl as we know it in brewing is naturally formed by brewers’ yeast during fermentation and also essentially completely assimilated by the same yeast during the latter stages of fermentation, with only minute amounts (0.02–0.10 ppm) remaining in the fermented product. The chemistry is well-known and can be explained to any reporter or consumer group if asked. There is never any volatilized diacetyl in a brewery. I have already received a phone call from a research organization asking questions on behalf of OSHA concerning diacetyl in a brewery or beer.

The following was adapted from an article on Wikipedia1:

In rare instances, bronchiolitis obliterans may be caused by inhalation of airborne diacetyl — a chemical used to produce the butter-like flavoring in many foods such as candy, microwave popcorn and wines. This first came to public attention when eight former employees of the Gilster-Mary Lee popcorn plant in Jasper, Missouri, developed bronchiolitis obliterans. In 2000, the Missouri Department of Health called in NIOSH to make a determination of the cause, and to recommend safety measures. After surveying the plant and each patient’s medical history, NIOSH recommended respiratory protection for all workers in microwave popcorn production. Due to this event, bronchiolitis obliterans began to be referred to in the popular media as ‘Popcorn Lung’ or ‘Popcorn Workers Lung’.[4][8][9]

One heavy consumer of microwaved popcorn has been diagnosed with this disease, which is the first known case involving a consumer.[13]

On 27 August, 2007, Weaver Popcorn Company of Indianapolis promised to replace the diacetyl butter flavor ingredient in Pop Weaver popcorn with another flavoring.[14]

In September 2007, Dr. Cecile Rose, pulmonary specialist at Denver’s National Jewish Medical and Research Center, warned federal agencies that consumers, not just flavoring or food factory workers, may be in danger of contracting bronchiolitis obliterans. David Michaels, of the George Washington University School of Public Health, first published Rose’s warning letter on his blog.[10][11][12]

On 4 September, 2007, the Flavor and Extract Manufacturers recommended reduction of diacetyl in butter-like flavorings. The next day ConAgra Foods announced that it would soon remove diacetyl from its popcorn products.[15]

On 16 January, 2008, it was announced that Wayne Watson, the Denver consumer who developed ‘popcorn lung’ after inhaling microwaved popcorn, was suing the Kroger grocery store chain and its affiliates. In the lawsuit, filed in U.S. District Court, Watson’s attorney claimed that the companies ‘failed to warn that preparing microwave popcorn in a microwave oven as intended and smelling the buttery aroma could expose the consumer to an inhalation hazard and a risk of lung injury.’[16]

Diacetyl is approved by the Food and Drug Administration as a safe flavor ingredient, but there is evidence to suggest that inhalation in large amounts is dangerous. There are currently no warnings from federal regulators about diacetyl.

In addition, scientists at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, have recently published the results of a study focusing on the implications that diacetyl used in popcorn and confectionery production may lead to the lung disease bronchiolitis obliterans syndrome (BOS), also known as obliterative bronchiolitis (OB).

(1) ”Diacetyl,” Wikipedia, The Free Encyclopedia, (accessed June 25, 2008).

(2) Morgan, D., Flake, G., Kirby, P., and Palmer, S. (2008). Respiratory toxicity of diacetyl in C57BI/6 mice. Toxicological Sciences ToxSci Advance Access. Published online on January 27, 2008. DOI: 10.1093/toxsci/kfn016.

Additional Notes

Scientists at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, said they conducted the study because of implications that the chemical (DIACETYL), which is used in popcorn and confectionery production, may lead to the lung e bronchiolitis obliterans syndrome (BOS), also known as obliterative bronchiolitis (OB).

Ray Klimovitz has been in the brewing industry for more than 40 years, having worked for Canadian Breweries Ltd. (Carling Brewing Company, U.S.A.), the Jos. Schlitz Brewing Company, and the Stroh Brewery Company. Klimovitz was director, brewing and special product development at Stroh’s in 1999 when Stroh’s ceased operations. Since October 1999, he has been involved in brewing and soft-drink consulting as president of Klimovitz Brewing Consultants, Inc. He is a former technical director for the Master Brewers Association of the Americas; project consultant for Sartorius, AG (Goettingen, Germany); VP product development for IZZE Beverage Company, Boulder, CO; and U.S. brewmaster for the Sleeman Brewing Company, Guelph, ON, Canada.




Brewing Resources

Ask the Brewmasters Technical Quarterly MBAA Webinars MBAA Podcasts Food Safety Brewery Safety Member Directory