Avoid artificial butter flavoring...in fact avoid any artificial colors and flavorings, which can contribute to a host of health problems.
Artificial Butter Flavor and "Popcorn Lung" Disease
"Beginning in the 1990's, factory workers in four Midwestern states have contracted a (previously) rare lung disease as a result of exposure to artificial butter flavoring used in microwave popcorn. The Environmental Protection Agency is now conducting its first study of the chemicals emitted from bags of microwave popcorn.
The National Institute for Occupational Safety and Health has linked diacetyl, a chemical in the popcorn flavoring, to the respiratory illness found in workers who mix it. Investigators believe this chemical becomes dangerous when it is heated and there is repeated exposure to large quantities over an extended period.
The EPA study began last fall when popcorn workers became ill at the Gilster-Mary Lee Corp. plant in Missouri, a company that produces artificial butter flavoring. Eight employees developed a disease that causes irreversible lung damage, and four needed lung transplants. Twenty-one other employees apparently also suffered adverse health effects.
The study, which should be completed this year, only examines the type and amount of chemicals emitted from microwave popcorn. According to the EPA, further research will be needed to determine health effects.
We question why the effects of such synthetic chemical additives on both workers and consumers were not studied before being allowed for use in this popular snack food.
Many brands of microwave popcorn also contain tartrazine (FD&C Yellow No. 5), which has been linked to hyperactivity, asthma and other health problems. "
This excellent site explores food additive issues, especially as they effect children: http://www.feingold.org