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Jan. 24, 2011
Contact: Office of Communications
Phone: 202-693-1999

OSHA revises National Emphasis Program to focus on protecting
workers from exposure to diacetyl and diacetyl substitutes

WASHINGTON – The Occupational Safety and Health Administration recently revised its National Emphasis Program (NEP) on Microwave Popcorn Processing Plants*. The purpose of this revised NEP is to minimize or eliminate worker exposure to the hazards associated with microwave popcorn manufacturing.

Diacetyl is a chemical used to add flavor and aroma to food and other products. Some workers who breathe diacetyl on the job have become disabled or have died from severe lung disease. Some manufacturers of microwave popcorn are now using diacetyl substitutes such as 2,3-pentanedione, diacetyl trimer and acetoin among others. Recent studies have shown that 2,3-pentanedione has produced similar health effects as diacetyl, and therefore, may also cause harm to workers.

"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.

For more safety and health information on diacetyl and other food flavorings, visit OSHA's Safety and Health Topics page on Lung Disease Related to Butter Flavorings Exposure. OSHA's Safety and Health Information Bulletin and companion Worker Alert recommend engineering and work practice controls for regulating diacetyl and diacetyl substitute exposures in the workplace.

Under the Occupational Safety and Health Act of 1970, employers are responsible for providing safe and healthful workplaces for their employees. OSHA's role is to assure these conditions for America's working men and women by setting and enforcing standards, and providing training, education and assistance. For more information, visit


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OSHA News Release - Table of Contents

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