Underscoring the importance of the distinction between a product and its component parts, a federal court in Louisiana refused to allow expert testimony that exposure to gasoline caused acute myeloid leukemia (“AML”) in a former gas station attendant and mechanic. See Burst v. Shell Oil Co., No. 14-209 (E.D. La. June 9, 2015).  Plaintiff claimed Defendant gasoline manufacturers negligently manufactured and sold gasoline containing benzene, and failed to warn foreseeable users of the health hazards from that gasoline.  

Plaintiff offered Dr. Robert Harrison, a medical doctor to testify that benzene causes AML, and that benzene caused Plaintiff’s husband to develop AML.  Defendants moved to exclude Dr. Harrison’s testimony as unreliable and irrelevant.  The Court granted Defendants’ motion, finding that, although the link between benzene and AML is well established, the expert failed to connect gasoline, the product at issue in this case, to AML. 

The Court noted the expert claimed to have used a methodology that involved “identify[ing] all relevant studies.”  Burst slip op. at *4.  Yet the expert did not cite a single study evaluating any connections between gasoline exposure and AML.  Instead, he relied on benzene-specific studies, and made “no attempt to demonstrate why benzene-specific studies can reliably support the conclusion that gasoline can cause AML.”  Id. at *5.  Moreover, the Court noted that reputable studies had been published that did not find a causal connection between gasoline and AML.  This, the Court held, left too big of a gap between the available data and the expert’s conclusions, rendering the expert’s opinion unreliable.