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

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

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

In a decision written by Chief Justice Wallace Jefferson, the court noted that “we observed that asbestos litigation had reached maturity” almost ten years ago. In that time, however, the court noted that asbestos claims had evolved, and that the judicial system has struggled to develop parameters for asbestos-related claims.

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

Effectively, the court said, Mr. Flores was not able to provide evidence that any asbestos exposure he suffered while working on Borg-Warner brake pads played a substantial role in his illness.

“This record,” Justice Jefferson wrote of the evidence presented at trial, “reveals nothing about how much asbestos Flores might have inhaled.”

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

“Nevertheless, absent any evidence of dose, the jury could not evaluate the quantity of respirable asbestos to which Flores might have been exposed or whether those amounts were sufficient to cause asbestosis,” he said. “Nor did Flores introduce evidence regarding what percentage of that indeterminate amount may have originated in Borg-Warner products.”

The court recognized that proving an asbestos exposure claim can be very difficult, especially given the long latency period that comes with some asbestos-related diseases, and that courts have struggled with the issue.

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

Additionally, he noted that even Mr. Flores' expert witnesses acknowledged that asbestos is “plentiful” in ambient air and, if simple 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 his asbestosis was caused by a particular product,” he said.

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

“Flores alleged two claims: negligence and strict liability,” he concluded. “Because each requires proof of substantial-factor causation, both fail.”