Exercising its authority to address Daubert challenges at the class certification stage, the Southern District of West Virginia refused to certify proposed Plaintiff classes in a toxic exposure case because it found the expert testimony on which they relied to be inadmissible. See Coleman v. Union Carbide, No. 11-0366 (S.D. W.Va. Sept. 30, 2013). Plaintiffs alleged that multiple Defendants were responsible for an alloy plant’s emissions over a period of decades. Coleman, slip op. at 3-9. 

Plaintiffs proposed two classes for certification, which were defined by whether individuals met certain exposure criteria, and sought a “comprehensive, court-supervised program of medical monitoring” in addition to a permanent injunction prohibiting Defendants from further emissions in excess of regulatory limits. Id. at 12-13. Applying Comcast Corp. v. Behrend, 133 S. Ct. 1426 (2013), in which the Supreme Court recently affirmed that courts may examine the merits of a claim at the class certification stage, the district court allowed Defendants to challenge Plaintiffs’ expert testimony under Daubert as part of their effort to defeat class certification. Id. at 52-54.

Noting that “the expert opinions in the case are the primary evidentiary means chosen by plaintiffs” to meet the class certification requirements, the court undertook an extensive analysis of the admissibility of testimony from two of Plaintiffs’ experts. Id. at 54. The court found that the experts’ opinions were not based on sufficient facts or data, and questioned their methodology. Id. at 84, 101.  Based on the exclusion of this expert testimony, the court found that “the proposed classes have, at a minimum, become unascertainable,” and concluded that Plaintiffs did not meet the requirements for class certification. Id. at 101, 106. In dicta, the court also noted that “no circuit court of appeals has ever approved certification of a medical monitoring class action,” and expressed reluctance to adopt a different approach. Id. at 103.