The U.S. House of Representatives Wednesday approved legislation that would force OSHA to develop interim standards limiting worker exposure to the artificial flavoring diacetyl. The House passed the legislation 260-154. The Senate has not yet considered it.

Exposure to diacetyl, the chemical that gives microwave popcorn its buttery flavor, has been linked to bronciolitis obliterans, a fatal lung disease. While the Food and Drug Administration has approved the use of diacetyl as a flavor ingredient, the concern is when workers inhale it in manufacturing settings.

The Bush administration and many House Republicans think the bill, H.R. 2693, "Popcorn Workers Lung Disease Prevention Act," sponsored by Rep. Lynn Woolsey (D-Calif.), is premature and that Congress is interfering with the work of OSHA, which might cause more harm than good, according to the Associated Press.

“We believe that it’s important to give OSHA time to complete a scientific study of diacetyl exposure and to issue a recommended exposure limit for the use of that chemical,” said Rep. Lincoln Diaz-Balart (R-Fla.). “Without a complete study, Congress may push manufacturers to use different chemicals that could be even more directly responsible for diseases.”

The bill requires OSHA to issue within 90 days an interim final standard to minimize workers’ exposure to diacetyl in popcorn and flavor manufacturing plants. If the bill becomes law, the agency would have to issue a final rule covering all workplaces where workers are exposed to diacetyl within two years.

The legislation also directs NIOSH to conduct a study to determine the potential exposure hazards of diacetyl and associated chemicals used in the production of microwave popcorn.

In lawsuits, hundreds of workers at food factories exposed to diacetyl have linked the chemical to cases of bronchiolitis obliterans, often called “popcorn lung.”

“It’s a travesty that OSHA has done nothing to regulate this chemical, while workers have fallen seriously ill and some have actually died,” Woolsey said. “That’s why it’s time for Congress to act to keep workers healthy and safe. Passing this important legislation is a step in the right direction.”

On Monday, OSHA announced actions it is taking to address concerns regarding diacetyl exposure in the workplace. The agency is initiating a rulemaking under section 6(b) of the Occupational Safety and Health Act and, and is issuing a Safety and Health Information Bulletin (SHIB) and a Hazard Communication Guidance.

OSHA also announced Wednesday a stakeholder meeting scheduled for Oct. 17, which will give the public an opportunity to share concerns about diacetyl exposure and allow OSHA to collect additional information regarding the matter.

Many microwave popcorn manufacturers have begun finding a flavoring substitute for diacetyl, according to AP.