Hold the microwave popcorn

Health experts and labor unions are demanding emergency safety standards to check an outbreak of lung disease among workers in microwave popcorn factories. What has taken them so long?

In 2003, a study linked the potential health risks from inhaling artificial butter flavors from microwave popcorn to lung disease. The Environmental Protection Agency (EPA) completed research on chemical emissions from popping and opening microwave popcorn, and diacetyl was one of several compounds for which it tested. Prior to 2003, studies in toxicology journals linked diacetyl -- a common food flavoring and main ingredient of artificial butter flavoring -- to disease in laboratory animals. Recently dubbed "popcorn workers' lung" in humans, the disease is a serious and irreversible inflammation of the airways leading to the lungs.

According to a group of scientists and former Occupational Safety and Health Administration officials, The EPA has not yet released the results of this study, even though thousands of workers have been exposed to artificial butter vapors containing diacetyl.

Some workers at microwave popcorn factories have been diagnosed with bronchiolitis obliterans, a rare and fatal lung disease. To date, one employee has died and several others are waiting on lung transplant lists. It is not clear how many workers have been affected, but thousands of workers have been exposed to artificial butter vapors containing diacetyl and at least one employee has died.

"This is a tragic example of the failure of the public health regulatory system," said David Michaels, associate chairman of the Department of Environmental and Occupational Health at George Washington University.

Even though the U.S. National Institute for Occupational Safety and Health has suggested that diacetyl, when used in artificial butter flavoring (as used in microwave popcorn), may be hazardous when heated and inhaled over a long period, it has not yet been determined whether consumption of microwave popcorn or foods that contain artificial butter flavoring could produce health risks, and additional risks are unknown until the EPA publishes its findings.

But case studies have already determined links between exposure to diacetyl and disease. In 1999, workers at a Gilster-Mary Lee Corp. popcorn plant in Jasper, Mo. were diagnosed with popcorn workers' lung. In 2000, eight more workers, whose job was to open bags of buttered microwave popcorn, developed the disease. The Missouri Department of Health and the CDC were notified. A study found that the plant workers had 3.3 times the national rate of pulmonary disease for smokers and 10.8 times the national rate for nonsmokers.

After the workers filed a lawsuit against manufacturers Gilster-Mary Lee Corp., the Environmental Protection Agency began an investigation into the chemical properties of microwave popcorn butter flavoring. On July 19, 2005, jurors awarded a popcorn plant worker in Missouri $2.7 million for his claim of diacetyl-induced respiratory problems. Instances of popcorn workers' lung have also been found in factories in California and Ohio.

Where is the Food and Drug Administration? The FDA only tests artificial flavorings based on ingestion safety, not inhalation safety. Which means that diacetyl inhalation is basically unregulated.