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.