Two bills are pending in the Texas legislature to overturn a significant toxic tort decision made by the state’s highest court. In Borg-Warner Corp. v. Arturo Flores, 232 S.W.3d 765 (Tex.2007), the court required plaintiffs to prove they had a sufficient level of exposure to the toxic substance, asbestos.

Earlier in April, a committee of the Texas Senate approved by a 6-2 vote a bill relating to the
standard of causation in claims involving mesothelioma caused by exposure to asbestos
fibers. The bill, S.B. 1123, introduced by Sen. Robert Duncan, R-Lubbock, would require a plaintiff to prove that a defendant ’s product or conduct was a substantial factor in causing the exposed claimant ’s injury by presenting qualitative proof that the asbestos exposure attributed to the defendant was substantial, and not merely de minimis, when considering (1) the frequency of the exposure;  (2) the regularity of the exposure; and (3) the proximity of the claimant to the source of the asbestos fibers.  A plaintiff would not be required to prove numerically the dose, approximate or otherwise, of asbestos fibers to which the claimant was exposed that are attributable to the defendant.

A House bill, introduced by Rep. Craig Eiland, D-Texas City, is still pending in committee. H.B. 1811 would require proof that the defendant ’s product or conduct was a substantial factor in causing the exposed person ’s injury, by showing that the exposure to the asbestos fibers for which that defendant is alleged to be responsible contributed to the cumulative exposure of the exposed person and was more than purely trivial when considering the following (same) qualitative factors: (1) the frequency of exposure; (2) the regularity of exposure; and (3) the proximity of the exposed person to the source of the asbestos fibers. Plaintiff need not prove, for any purpose, a quantitative dose, approximate quantitative dose, or estimated quantitative dose of asbestos fibers to which the exposed person was exposed.

Such language would significantly lower the standard for providing causation in mesothelioma litigation. Perhaps the most widely cited standard for proving causation in asbestos cases is the Lohrmann “frequency, regularity, and proximity” test. Lohrmann v. Pittsburgh Corning Corp., 782 F.2d 1156 (4th Cir.1986). The court there rejected a standard that if the plaintiff can present any evidence that a company’s asbestos-containing product was at the workplace while the plaintiff was at the workplace, a jury question has been established as to whether that product proximately caused the plaintiff’s disease. Instead, the court concluded that to support a reasonable inference of substantial causation from circumstantial evidence, there must be evidence of exposure to a specific product on a regular basis over some extended period of time in proximity to where the plaintiff actually worked.

While the test seemed to be tighter standard than the plaintiffs’ proposed test, since a plaintiff must prove more than a casual or minimum contact with the product, in reality the test has loosened the traditional standards for substantial factor causation. In Borg-Warner, the court held that a “frequency, regularity, and proximity” test does not, in itself, capture the role of causation as an essential predicate to liability. As in many jurisdictions, the word “substantial” in substantial factor is used to denote the fact that the defendant’s conduct has such an effect in producing the harm as to lead reasonable people to regard it as a cause, using that word in the popular sense, in which there always lurks the idea of responsibility, rather than in the so-called philosophic sense, which includes every one of the great number of events without which any happening would not have occurred.

Substantial factor in a toxic tort case cannot be analyzed without recognizing that one of toxicology’s central tenets is that “the dose makes the poison.” This notion was first attributed to sixteenth century philosopher-physician Paracelsus, who stated that all substances are poisonous-there is none which is not; the dose differentiates a poison from a remedy. Even water, in sufficient doses, can be toxic. Dose refers to the amount of chemical that enters the body, and, is probably the single most important factor to consider in evaluating whether an alleged exposure caused a specific adverse effect. Not all asbestos exposures cause cancer, and the scientific literature shows that more exposure leads to more disease (dose-response).

Plaintiffs showed nothing about how much asbestos Flores might have inhaled. He was exposed to “some asbestos” on a fairly regular basis for an extended period of time. 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 his disease. Nor did Flores introduce evidence regarding what percentage of that indeterminate amount may have originated in defendant Borg-Warner products. Plaintiffs did not prove the asbestos content of other brands of brake pads or how much of Flores’s exposure came from grinding new pads as opposed to blowing out old ones. Plaintiff need not show dose with mathematical precision.  But in a case like this, proof of mere frequency, regularity, and proximity is necessary but not sufficient, said the court, as it provides none of the quantitative information necessary to support causation under Texas law.

The proposed legislation would overturn that clear and compelling logic.