SOUTH GATE, Calif. - She was once in constant motion; her co-workers compared her to a roadrunner because of the way she darted around the workplace. But now Irma Ortiz sits at the edge of her couch, too winded to sweep her patio or walk her son to school without resting. She is slowly suffocating.

Ortiz, 44, is among a group of California food-flavoring workers recently diagnosed with bronchiolitis obliterans, a rare and life-threatening form of fixed obstructive lung disease. Also known as popcorn workers lung, because it has turned up in workers at microwave-popcorn factories, the disease destroys the lungs. A transplant is the only cure.

Since 2001, academic studies have shown links between the disease and a chemical used in artificial butter flavor called diacetyl. Flavoring manufacturers have paid out more than $100 million as a result of lawsuits by people sick with popcorn workers lung over the past five years. One death from the disease has been confirmed.

But no federal laws regulate the chemical's use. The Occupational Safety and Health Administration is still deciding what standards to set for workers who handle it. In late April, the head of OSHA, Assistant Secretary of Labor Edwin G. Foulke Jr., testified before Congress that the agency would begin inspecting microwave-popcorn factories this month.

While critics charge that OSHA has stalled, California is moving ahead. State Assemblywoman Sally Lieber, a Democrat, has introduced a bill to ban the use of diacetyl.

Since the first California case of popcorn workers lung was diagnosed just over two years ago, state health officials have screened workers at each of the state's 29 food-flavoring plants, looking for breathing trouble. The screenings lay the groundwork for state regulation of diacetyl and provide the first comprehensive data on flavoring workers outside popcorn plants.

So far, the California Division of Occupational Safety and Health, or Cal/OSHA, has found eight flavoring workers with fixed obstructive lung disease, most of those with bronchiolitis obliterans. Twenty-two more have below-normal lung capacity, which may be the beginning of the disease.

"They're finding it there because they're looking there," said David Michaels of the department of environmental and occupational health at George Washington University. Michaels, assistant secretary of energy in the Clinton administration, accuses OSHA of "regulatory paralysis."

"It's not some carcinogen where you get cancer 30 years from now or something. The people are dying right in front of you," Michaels said. "You can't wait until you have all the evidence. You have to regulate it."

Even less is known about the health effects of eating diacetyl in butter-flavored popcorn, or breathing the fumes after the bag is microwaved. The Environmental Protection Agency has studied the fumes but is waiting for the industry to review the study before releasing it. The Food and Drug Administration has diacetyl on its list of substances "generally recognized as safe," but has not studied it.