In an effort to reduce worker exposure to diacetyl, the Occupational Safety and Health Administration has revised its National Emphasis Program (NEP) on Microwave Popcorn Processing Plants. Diacetyl, a chemical used to add flavor and aroma to popcorn and other foods, has been linked to lung disease when inhaled.

According to the agency, some workers who breathe diacetyl on the job have become disabled or have died due to pulmonary disease. Although a number of manufacturers of microwave popcorn have switched to diacetyl substitutes such as 2,3-pentanedione, diacetyl trimer and acetoin, recent studies have shown that 2,3-pentanedione can cause similar harmful health effects as diacetyl.

"It is alarming that workers continue to be at risk of dying from exposure to diacetyl and diacetyl substitutes," said Assistant Secretary of Labor for Occupational Safety and Health Dr. David Michaels. "Illnesses and death from these chemicals are preventable and this revised directive will help ensure that employers use necessary measures to protect workers from this hazard."

OSHA's efforts to minimize or eliminate workers' exposure to microwave popcorn manufacturing hazards include inspection targeting, directions for controlling chemical hazards, and extensive compliance assistance. Inspections conducted under this NEP will target facilities where workers are manufacturing or processing microwave popcorn.

Currently, OSHA has permissible exposure limits (PEL) for some diacetyl substitutes, however most flavorings do not have PELs. Additionally, microwave popcorn manufacturing facilities are subject to other applicable OSHA mandatory standards including Respiratory Protection and Hazard Communication.