Excluding Chemical Risk Assessment Evidence From the Courtroom

When governmental or quasi-governmental agencies formulate a chemical risk assessment, it is part of their legitimate exercise of public health, policy-oriented regulation.  Regulators often develop risk assessments due to scientific uncertainty concerning the toxicity of a particular compound and utilize conservative risk models in the interest of protecting public health and the environment.  Thus, when a substance is labeled “possibly carcinogenic” or even “probably carcinogenic” by an agency, it may have little or no bearing on general and specific causation issues.

For this reason, risk assessments, and the assumptions that go into making them, have no legitimate place in toxic tort litigation.  Agency classifications and risk assessment certainly cannot legitimately be used by a toxic tort plaintiff to help establish his case-in-chief.  Agency classification and risk assessments are based upon standards that very significantly from the burdens of proof in a courtroom.  Thus, they are not legally relevant and pose a significant risk of confusion to jurors and prejudice to defendants. 

In a compelling article appearing in the Bloomberg BNA Toxics Law Reporter (February 3, 2012) titled, “When ‘Likely’ Does Not Mean ‘More Likely Than Not’: The Dangers of Allowing Government Chemical Classifications and Numeric Risk Assessments at Trial,” Mark P. Fitzsimmons and Leah M. Quadrino at Steptoe and Johnson, and Sneha Desai at BASF, describe how governmental agencies perform risk assessments and how the assumptions employed in reaching these risk assessments can easily mislead lay persons serving on juries in assuming that particular chemicals are carcinogenic to humans when, in fact, they may not be. 

Frequently, plaintiffs seek to introduce as evidence general and specific causation and increased risk.  The authors observe that the critical distinction between a regulatory classification of a chemical and the burden of proof required in court has been widely litigated.  Thus, in Gates v. Rohm and Haas Co., No. 10-108, 2011 U.S. App. LEXIS 17756, *33 (3d Cir. Aug. 25, 2011), the Third Circuit held that, “plaintiffs could not carry their burden of proof for a class of specific persons simply by citing regulatory standards for the population as a whole.” 

Similarly, other courts have excluded expert testimony for relying on regulatory ratings or standards in determining whether a plaintiff’s exposure to a substance above regulatory limits was sufficient to establish causation.  Baker v. Chevron USA Inc., 680 F.Supp. 2d. 865, 880 (S.D. Ohio 2010).  Defense counsel also must be vigilant against a court’s use of numeric risk assessment as a benchmark for determining increased risk.  The takeaway is that “probably” in a regulatory context does not mean “more probable than not” in a tort context.

Lenient Asbestos Causation Standard Rejected In Toxic Tort Case

Guest Blogger M.C. Sungaila, one of California’s most best known appellate advocates,  briefed and successfully argued the Molina appeal discussed here on behalf of Shell and Chevron. 

A California appeals court rejected the lenient increased risk causation standard used to establish causation in asbestos cases in a toxic tort case not involving asbestos.  The Second Appellate District of the California Court of Appeal in Los Angeles upheld a defense verdict last month, in  Molina v. Shell Oil Company et al, determining that the trial court correctly refused to charge the Rutherford “increased risk” instruction applicable in asbestos cases because the ability of a product to cause the type of harm suffered by the plaintiff was hotly contested.

After a five-week trial and four days of deliberations in the trial court, a jury concluded that William Molina – who suffered from a variety of cancers and other ailments — was not entitled to damages for his alleged exposure to defendants’ solvents during his 17-year career at a Firestone tire plant. The jury found that neither the solvents’ design nor any warning associated with them was a substantial factor in causing Molina’s non-Hodgkins lymphoma (NHL). Molina appealed, claiming among other things that the causation instruction used in California’s asbestos litigation should have been given to the jury.

The appeals court court stopped short, however, of holding that the more liberal  Rutherford causation standard can never apply outside the asbestos context. Nevertheless, the Court of Appeal addressed a question repeatedly posed to trial courts throughout the state over the last five years: should a more lenient causation standard adopted by the California Supreme Court in the asbestos context be extended to other types of toxic tort cases like benzene? The appellate court’s answer was a qualified "no".

Causation, of course, is an essential element of a tort action. California has definitively adopted the substantial factor test of the Restatement Second of Torts for cause-in-fact determinations. Implicit in the substantial factor causation standard in a toxic tort case is the requirement of proving both that a chemical can cause a particular adverse health effect and that it did cause that effect in the plaintiff.  In other words, proof of causation necessarily includes a threshold determination whether, in reasonable medical probability, a particular chemical is capable of causing in humans the type of harm suffered by the plaintiff (i.e., “general causation”).  If the chemical does not possess that capacity, the chemical cannot have caused the particular plaintiff’s claimed harm.  But if the chemical does have that capacity, then the causation inquiry shifts to whether the plaintiff’s exposure to the chemical in question was, in reasonable medical probability, a substantial factor in causing this particular plaintiff’s harm (i.e., “specific causation”). Toxic tort causation also involves a threshold element of exposure. In order to determine whether an exposure is a possible contributing factor to a plaintiff’s injury, ‘[f]requency of exposure, regularity of exposure, and proximity of the . . . product to [the] plaintiff are certainly relevant.” (Lineaweaver v. Plant Insulation Co. (1995) 31 Cal.App.4th 1409, 1416.)

Molina contended that California Civil Jury Instruction (CACI) No. 435, a relaxed “increased risk” causation instruction, should have been given because of the difficulties of proving cancer causation. The defendants successfully urged that the increased risk instruction under Rutherford should not apply where, as in Molina’s case, the ability of a chemical to cause a particular type of cancer is hotly disputed and far from well-established.

In Rutherford v. Owens-Illinois, Inc. (1997) 16 Cal.4th 953, 960, at the end of the first phase of trial, the jury concluded that exposure to asbestos fibers proximately caused the decedent’s lung cancer and awarded damages. After this phase, several defendants settled. In a second phase of trial, the jury was asked to apportion damages and allocate fault to the remaining defendant, Owens-Illinois. Owens-Illinois objected to the use of an instruction in the second phase of trial which stated that, once the plaintiff had established both that he was exposed to defendants’ asbestos and that his injuries were legally caused by asbestos exposure generally, the burden then shifted to the defendant to establish that its product was not a legal cause of the plaintiff’s harm.

The California Supreme Court rejected the use of the burden-shifting instruction as too “fundamental” a departure from traditional substantial factor causation. However, the Court concluded that, rather than be required to “trace the unknowable path of a given asbestos fiber,” a “plaintiff[] may prove causation in [an] asbestos-related cancer case[] by demonstrating that the plaintiff’s exposure to defendant’s asbestos-containing product in reasonable medical probability [fn. omitted] was a substantial factor in contributing to the aggregate dose of asbestos the plaintiff or decedent inhaled or ingested, and hence to the risk of developing asbestos-related cancer, without the need to demonstrate that fibers from the defendant’s particular product were the ones, or among the ones, that actually produced the malignant growth.”

Thus, in Rutherford, “it was already determined what caused the plaintiff’s illness—asbestos. The only remaining issue before the Court was the proper standard for determining who manufactured or supplied the asbestos that caused the plaintiff’s illness.” (Loewen, Causation in Toxic Tort Cases: Has the Bar Been Lowered? (Spring 2003) 17 Nat. Res. & Env’t 228, 229 (hereafter Loewen).) As one commentator observed: “This is undoubtedly the reason that the Rutherford court consistently and repeatedly limited its holding to ‘asbestos-related cancer cases’: its language linking risk to cause was expressly limited to cases where it has been determined that the cancer was ‘asbestos-related.’” (Ibid.) Accordingly, Rutherford does not apply in a case like this, where the ability of the defendants’ products to cause the plaintiff’s type of cancer is hotly disputed.

In Molina’s case, defendants’ toxicology expert testified that solvents do not cause NHL.  While one plaintiffs’ expert asserted that solvents could cause NHL, another plaintiffs’ expert testified that the evidence of a causal link between benzene and NHL was “weak” and therefore he could not state to a reasonable degree of medical probability that benzene could cause NHL.  Moreover, one of plaintiffs’ experts admitted that NHL is frequently idiopathic or of unknown origin.

The Court of Appeal agreed that the trial court correctly refused the Rutherford “increased risk” instruction applicable in asbestos cases. Rutherford involved a very different situation: in that case, a jury had already determined that the asbestos had caused the plaintiff’s lung cancer. The only remaining question was which manufacturers were responsible. The cause of Mr. Molina’s NHL, however, was not established.  In fact, the capability of defendants’ products to cause Mr. Molina’s injury was one of the most critical and hotly disputed issues in the case.