Defend causation precedent in asbestos suits

Under settled principles of tort law, a plaintiff seeking compensatory damages in a product-liability case must show that the defendant's product was a "but for" cause of his or her injury. Even in the typical toxic tort case, such a showing requires not only proof of exposure to the defendant's product, but also exposure to a sufficient dose of the defendant's product to actually cause the plaintiff's disease.

But what about plaintiffs in asbestos litigation who have been exposed to asbestos from many different sources or products over the course of their lifetimes? What must they show to establish that a given asbestos defendant legally caused their asbestos-related injuries?

The California Supreme Court attempted to answer this question 20 years ago in Rutherford v. Owens-Illinois, Inc. Recognizing that all asbestos products (and exposures) are not the same, Rutherford insisted that ordinary causation rules should still apply in asbestos tort cases.

Under the test announced in Rutherford, asbestos plaintiffs seeking money damages in California courts must not only "establish some threshold exposure to the defendant's defective asbestos-containing products," but they must also show a "reasonable medical probability that a particular exposure or series of exposures" was a "substantial factor" in causing their asbestos-related injury. Thus Rutherford endorsed standard causation principles, and remains binding law in the state of California.

Although the court in Rutherford emphasized that any proper application of this substantial-factor test must account for the "length, frequency, proximity and intensity of the exposure" as well as "the peculiar properties of the individual product," California trial and appellate courts have increasingly watered down or altogether ignored this important aspect of the test.

One of the most alarming departures from Rutherford's substantial-factor test has been the California courts' increased acceptance of the "every exposure" theory of causation in asbestos litigation. Under this controversial theory, because asbestos-related diseases develop over time in a cumulative, dose-responsive process, each and every exposure to asbestos during a plaintiff's lifetime -- no matter how infinitesimal -- "contributes" to that plaintiff's asbestos-related disease.

But the "every exposure" theory is logically incoherent, because even its proponents readily admit that everyday background exposures to ambient asbestos -- even if they contribute millions of fibers to a person's lungs over a lifetime -- do not contribute to asbestos-related diseases. Indeed, according to the Centers for Disease Control and Prevention's Agency for Toxic Substances and Disease Registry, "[l]ow levels of asbestos that present little, if any, risk to your health can be detected in almost any air sample."

So, when opining on "every exposure" causation in asbestos cases, plaintiffs' experts routinely exclude the kind of unavoidable and pervasive background exposures to asbestos that everyone in modern industrial societies experiences. Yet those exposures are equally "cumulative" and can, over a person's lifetime, far exceed the level of workplace exposures that the selfsame experts attribute as the sole cause of the plaintiff's disease.

At bottom, the "any exposure" theory eliminates "but for" causation by collapsing Rutherford's two-part substantial-factor test into one, easily satisfied showing: To establish causation, a plaintiff need only present threshold evidence of any exposure to the defendant's asbestos-containing product. Such a "test" not only relieves a plaintiff of any real burden to prove causation, but it also effectively shifts the burden to the defendant to prove that its products did not cause the plaintiff's asbestos-related injury.

Because different sources of asbestos have widely divergent toxicities, the "every exposure" theory of causation allows plaintiffs' counsel to sue potentially hundreds of defendants whose alleged contribution to the plaintiff's disease is not only trivial, but far below the dosage thresholds known to cause such diseases as mesothelioma, lung cancer, and asbestosis. This relaxation of the causation burden has the practical effect of requiring a manufacturer to serve as an insurer to indemnify anyone whose injury is even remotely connected to the manufacturer's product.

As lower California courts have moved further and further away from the sensible causation rule announced in Rutherford, California's civil justice system has become a glaring outlier. Indeed, the 9th and 6th U.S. Circuit Courts of Appeals have joined several state supreme courts -- including Georgia, Texas and Pennsylvania -- in squarely rejecting the "every exposure" theory of causation. As the 6th Circuit aptly explained in Moeler v. Garlock Sealing Technologies, embracing the "every exposure" theory "would be akin to saying that one who pours a bucket of water into the ocean has substantially contributed to the ocean's volume."

Given its outlier status on many asbestos-related liability issues, California has emerged as a popular magnet jurisdiction for plaintiffs' counsel specializing in asbestos litigation. Most recently, in Phillips v. Honeywell International, Inc., 2017 DJDAR 2552 (March 17, 2017), plaintiffs were allowed (over Honeywell's objections) to establish causation by presenting expert testimony that any "identified exposure" to any type of asbestos -- in this case, replacement automotive brakes that the decedent occasionally installed -- was necessarily a substantial factor in causing the decedent's cancer.

On appeal, the 5th District Court of Appeal affirmed but made no serious attempt to harmonize the obvious contradiction between the trial court's "every exposure" theory and Rutherford's substantial-factor test. Honeywell, joined by several amici curiae, petitioned the California Supreme Court for discretionary review, which was denied. Unfortunately, the lower courts' runaway intransigence regarding the "every exposure" theory of causation is not going to correct itself anytime soon.

By effectively relieving plaintiffs of their burden to prove causation in even the most tenuous cases, the lax evidentiary threshold the "every exposure" theory makes possible has had the unintended consequence of reducing the amount of compensation available for those plaintiffs who can legitimately establish causation under traditional standards. As asbestos litigation increasingly comprises a disproportionate share of the docket in all California courts, the need for clarity on the evidentiary standard for proving causation in toxic tort cases could hardly be greater. Yet the California Supreme Court has denied at least a half-dozen petitions for review related to the causation standard for asbestos-related claims. Twenty years after Rutherford, it's high time the court rolled up its sleeves and got to work restoring the standard causation principles that lower courts have undermined.