SAN FRANCISCO — For years, Braxton Berkley was exposed to chemicals while helping build top-secret military planes at Lockheed Martin’s storied Skunk Works plant. He says those chemicals made him ill — but his case reached a dead end at the state’s highest court.

The California Supreme Court has refused to hear his appeal not on legal merits, but because four of the seven justices cited a conflict of interest because they controlled stock in oil companies that provided some of the solvents at issue in the case.

“It’s unfair, and I am very disgusted with the courts,” Mr. Berkley, who worked at Lockheed during the height of the Cold War, said. He is now a minister in Pacoima, Calif. He suffers from diabetes and arthritis that he says were caused by the chemicals. “A lot of my friends died because of the toxic chemicals we handled.” It’s common for at least one justice to bow out of a case because of a financial or personal conflict. Chief Justice Ron George, for instance, recuses himself from cases handled by the prominent law firm where his son practices. In those situations, an appellate judge is temporarily appointed to the Supreme Court to hear that case.

Justice George said the remaining justices decided to dismiss the case because they were concerned that a Supreme Court ruling made with a majority of temporary justices wouldn’t hold the same weight as an opinion of the permanent court.

“This is a very unusual situation, and I hope it doesn’t recur,” Justice George said.

Some legal advocates say the justices should be required to put their stock holdings into a blind trust. But California’s Administrative Office of the Courts has ruled that this is impossible because justices are required to closely manage their portfolios, Justice George said. State law says judges have a duty to know about any personal financial conflicts so they can recuse themselves if a conflict arises.

The court’s action has been the talk of the appellate bar, leaving lawyers on both sides in disbelief and law professors scratching their heads for a precedent.

“It’s an odd one,” a Santa Clara University law professor, Gerald Uelmen, said.

That’s little consolation to Mr. Berkley and his 24 former coworkers involved in the suit who have sought a multimillion-dollar verdict to pay for medical bills, pain, and suffering. Now, even their lawyers concede the case is dead.

The Supreme Court initially agreed to hear the Lockheed case in 2005 to settle an important legal question of how much leeway a judge has in barring expert witnesses from testifying.

Mr. Berkley and hundreds of other workers claimed that chemicals used to degrease parts and wash their hands made them ill. The cases began going to trial a decade ago in groups of about a dozen each. When the court agreed to hear Mr. Berkley’s case, which named ExxonMobil Corp. and Unocal Corp., only Justice Ming Chin had a conflict because of the stock he owned.

A judge had ruled in 2001 that the workers’ central witness, a scientist, lacked enough evidence to testify that the solvents Mr. Berkley and his colleagues handled caused their various diseases.

Then, last year, Justice Marvin Baxter’s aunt died and he was made executor of her estate. He became the fourth justice to control oil company stock involved in the case. When Chevron bought Unocal in August 2005, Justices Carol Corrigan and Joyce Kennard had also found themselves owning stock in oil companies entangled in the case.

Instead of appointing four temporary judges, Justice George said, the remaining justices decided in November to dismiss the case and wait for another case to come before them to settle the expert witness question. No such case currently exists.

Meanwhile, the other cases against Lockheed have mostly fizzled out, and one $760 million verdict was reversed on appeal. Justice George said the Lockheed workers had their cases thoroughly reviewed by trial and appellate judges.

“It’s not as if they didn’t have their day in court,” Justice George said.