NIOSH published a guide for health care providers on diacetyl, saying severe obstructive lung disease has been identified in people who work with flavoring chemicals containing diacetyl, including butter flavoring. Cases of severe lung disease have occurred in microwave popcorn plants and flavoring production plants, NIOSH said. Lung biopsies in some affected people have shown the presence of a rare condition, constrictive bronchiolitis obliterans (also referred to as constrictive bronchiolitis, obliterative bronchiolitis, and bronchiolitis obliterans) and in some workers, fixed airways obstruction has been severe enough to be fatal, the agency said. Meanwhile NIOSH has sought public comment on its draft document "Criteria for a Recommended Standard: Occupational Exposure to Diacetyl and 2,3-pentanedione".
