House Democrats on Wednesday ordered federal safety regulators to limit popcorn plant workers' exposure to a flavoring chemical linked to a lung ailment, saying further delay could cost lives.

The lack of an Occupational Safety and Health Administration standard on diacetyl "has endangered the health of families," said Rep. Betty Sutton, D-Ohio. "That is why we have to act today. Workers should never have to choose between their health and feeding their families."

But the Bush administration and House Republicans think the Democrats' bill is premature, and Congress' interference with OSHA's work may cause more harm than good.

"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."

Diacetyl occurs naturally in foods such as butter, cheese and fruits, and the Food and Drug Administration has approved its use as a flavor ingredient. The concern is when workers inhale it in manufacturing settings — either in making the flavoring or adding it to food products ranging from popcorn to pound cakes.

In a number of lawsuits, workers who were exposed to diacetyl have linked the chemical to cases of bronchiolitis obliterans, a rare life-threatening disease often called popcorn lung. Workers suffering from the progressive lung disease can be forced to undergo lung transplants to survive.

The Democrats' legislation gives OSHA three months to tell microwave popcorn production and packaging establishments and all flavoring manufacturing locations using diacetyl to limit exposure to the chemical; institute air monitoring, medical surveillance and safety labeling; and require the wearing of protective clothing and equipment for workers exposed to it.

Two years after the legislation is signed, the rules would apply to everywhere diacetyl is processed or used.

"OSHA has not acted, so today we will," said Rep. Robert Andrews, D-N.J.

The House passed the legislation 260-154. The Senate has not yet considered the bill.

A call to OSHA on Wednesday was not immediately returned.

ConAgra Foods Inc., General Mills Inc. and the American Pop Corn Company already have said they would stop using diacetyl. Together those companies accounted for more than 80 percent of the market for microwave popcorn over the past 12 months, according to the research firm Information Resources Inc.

Last year, the National Institute for Occupational Safety and Health, or NIOSH, issued a report that found several employees at a microwave popcorn plant were diagnosed with lung disease.

NIOSH determined that inhaling the butter flavoring put workers at risk for the lung disease. Since then, OSHA has increased inspections in places that make butter-flavor popcorn, and on Monday announced it had started the rulemaking process on diacetyl.

But in unusual criticism of the Republican administration, Rep. Howard "Buck" McKeon, R-Calif., said OSHA was silent on what it would do about diacetyl while House Democrats were working on this bill.

"In fact, if the administration had simply been forthright with Congress about its plans, we might not be here considering this questionable legislation at all," he said.

Republicans, including the White House, argued that Democrats' attempt to circumvent OSHA's decision-making process could hurt more than help.