Plaintiffs in asbestos cases must show that their exposure toasbestos-containing products was a substantial factor in theirdeveloping asbestosis, the Texas Supreme Court Ruled on today.

The case, titled Borg-Warner v. Flores, was initially filed bybrake mechanic Arturo Flores in 2001, claiming that he haddeveloped work-related asbestosis from asbestos in brake pads.

Mr. Flores specifically claimed that this exposure came frombrake pads manufactured by Borg-Warner between 1972 and 1975 thathe used five to seven times per week. Borg-Warner is now known asBurns International Services Corp.,

In a decision written by Chief Justice Wallace Jefferson, thecourt noted that “we observed that asbestos litigation had reachedmaturity” almost ten years ago. In that time, however, the courtnoted that asbestos claims had evolved, and that the judicialsystem has struggled to develop parameters for asbestos-relatedclaims.

“While science has confirmed the threat posed by asbestos, wehave not had the occasion to decide whether a person's exposure to'some' respirable fibers is sufficient to show that a productcontaining asbestos was a substantial factor in causingasbestosis,” the court said, adding that “we conclude that it isnot” and reversing the decision of the lower courts.

Effectively, the court said, Mr. Flores was not able to provideevidence that any asbestos exposure he suffered while working onBorg-Warner brake pads played a substantial role in hisillness.

“This record,” Justice Jefferson wrote of the evidence presentedat trial, “reveals nothing about how much asbestos Flores mighthave inhaled.”

Mr. Flores, he said, performed roughly fifteen to twenty brakejobs per week for over thirty years, and had certainly been exposedto “some asbestos” on a regular basis during that time period.

“Nevertheless, absent any evidence of dose, the jury could notevaluate the quantity of respirable asbestos to which Flores mighthave been exposed or whether those amounts were sufficient to causeasbestosis,” he said. “Nor did Flores introduce evidence regardingwhat percentage of that indeterminate amount may have originated inBorg-Warner products.”

The court recognized that proving an asbestos exposure claim canbe very difficult, especially given the long latency period thatcomes with some asbestos-related diseases, and that courts havestruggled with the issue.

A California court, Justice Jefferson noted in the ruling,offered the idea that a plaintiff need only prove that the asbestosthey were exposed to was a substantial factor in the overall doseof asbestos to which they were exposed and which caused theirillness.

Additionally, he noted that even Mr. Flores' expert witnessesacknowledged that asbestos is “plentiful” in ambient air and, ifsimple exposure were the threshold for developing asbestosis, then“everyone” would be susceptible.

“Given asbestos' prevalence, therefore, some exposure'threshold' must be demonstrated before a claimant can prove hisasbestosis was caused by a particular product,” he said.

Mr. Flores and his attorney offered no proof regarding theasbestos content of dust ground off of Borg-Warner pads, or thedust from any other pads, Justice Jefferson said, and thus thecourt could not uphold his claim.

“Flores alleged two claims: negligence and strict liability,” heconcluded. “Because each requires proof of substantial-factorcausation, both fail.”