In an asbestos-related products liability and negligence case, the Supreme Court ruled in favor of Deborah Hankinson’s client, Borg-Warner, holding a plaintiff must prove that exposure to the defendant’s product was a “substantial factor” in bringing about his asbestosis. The expert’s testimony that plaintiff had been exposed to “some asbestos” was insufficient. Instead, the plaintiff was required to introduce evidence showing the approximate amount of Borg-Warner fibers to which he had been exposed. The plaintiff further had to establish and that this exposure sufficiently contributed to the total dose of asbestos he inhaled such that it could be considered a substantial factor causing his asbestosis. Borg-Warner Corp. v. Flores, 232 S.W.3d 765 (Tex. 2007).