Diacetyl is a component of the artificial butter flavoring found in microwave popcorn. Exposure during the manufacturing process can cause a lung disease called bronchiolitis obliterans which reduces quality of life and causes premature mortality. Unfortunately, the disease has acquired the moniker "popcorn workers lung." While Congress is pushing for the Occupational Safety and Health Administration (OSHA) to issue a new regulation, the agency has taken a positive (albeit belated) step by examining regulations already on the books which could improve the situation.