WEDNESDAY April 16, 2008 (foodconsumer.org) -- A new study published in the journal, Toxicological Sciences found exposure to diacetyl, the artificial butter flavor chemical widely used in popcorn can harm the nose and airways of mice.

Diacetyl has been implicated in human obliterative brochiolitis or OB, a lung disease. Popcorn factory workers and at least one popcorn consumer in the United States OB after long term exposure to the chemical.
reportedly developed

In the study, Scientists at the National Institute of Environmental Health Sciences (NIEHS) let mice inhale diacetyl vapors for three months and found the mice developed lymphocytic bronchiolitis, a precursor of OB.   But none was diagnosed with OB.

The level of exposure to diacetyl and duration of the exposure was comparable to what may be experienced by microwave popcorn workers, said Daniel L. Morgan, Ph.D., coauthor of the study and head of the Respiratory Toxicology Group at the NIEHS.

The researchers concluded that these findings suggest that workplace exposure to diacetyl contributes to the development of OB in humans, but more study is needed.