Diacetyl a Chemical Linked to the Development of Serious Disorder. Diacetyl, a chemical linked to the development of a serious disorder known as Popcorn Workers Lung, has been shown to cause lung damage in lab mice. Popcorn Workers Lung, also known as obliterative bronchiolitis, is a debilitating but rare lung disease, which has been detected recently in workers who inhale significant concentrations of the flavoring in microwave popcorn packaging plants.
Diacetyl is used to give microwave popcorn and other snacks a buttery flavor. In 2003 and 2004, the National Institute on Occupational Safety and Health found an association between the toxic substance and the development of Popcorn Workers Lung among hundreds of workers at six Midwestern popcorn factories. Last April, the Centers for Disease Control (CDC) reported that workers at food flavoring factories, as well as popcorn plants, were at risk for the disease.
Popcorn Workers Lung is a potentially life threatening ailment, for which the only cure is a lung transplant. The disease was thought to be limited to people working in the flavorings industry. But last July, Dr. Cecile Rhodes informed the Food & Drug Administration (FDA) that one of her patients had contracted the disease. The patient had been consuming several bags of butter-flavored microwave popcorn on a daily basis for at least 15 years. According to the CDC, this is the first report of Popcorn Workers Lung in a consumer. That victim has since filed a lawsuit against the company that produced the microwave popcorn he favored.
Mice Developed Lymphocytic Bronchiolitis
This latest diacetyl study was conducted by scientists at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health. Lab mice were made to inhale diacetyl vapors over a three month time period. The mice developed lymphocytic bronchiolitis — a potential precursor of Popcorn Workers Lung. None of the mice, however, developed that disease.
“This is one of the first studies to evaluate the respiratory toxicity of diacetyl at levels relevant to human health. Mice were exposed to diacetyl at concentrations and durations comparable to what may be inhaled at some microwave popcorn packaging plants,” Daniel L. Morgan, Ph.D., head of the Respiratory Toxicology Group at the NIEHS said in a press release.
Dr. Morgan co-authored on the diacetyl study that appears online in the journal, Toxicological Sciences. The study was done in collaboration with Duke University researchers. The authors conclude that these findings suggest that workplace exposure to diacetyl contributes to the development of Popcorn Workers Lung in humans, but more research is needed.
In 2007, several makers of microwave popcorn, including ConAgra, General Mills and American Popcorn Co., took steps to remove diacetyl from their products. There has also been a movement to convince federal regulators to police the use of diacetyl in the workplace, but those efforts have had mixed results. The Occupational Safety and Health Administration (OSHA), which sets limits on how much of a dangerous substance a worker can be subjected to, said in 2000 that it had no standards for the flavoring and that it wasn’t a problem because the FDA considered diacetyl “safe.” For its part, the FDA has maintained that it has no jurisdiction to evaluate hazards posed by breathing vapors from food additives. It was only last year that OSHA started to investigate diacetyl exposure in snack food industry workers, and that agency is expected to look into setting standards for workers next month.