Plaintiffs involved in toxic tort cases are required to establish both general and specific causation, typically through expert testimony. Experts need to demonstrate that a particular chemical exposure is capable of causing the specific injury in question. For this demonstration, it is necessary for the plaintiff’s exposure to surpass the chemical’s minimum harmful level, referred to as the “threshold dose.”
The Eleventh Circuit previously clarified this concept in its decision on the In re Deepwater Horizon BELO litigation, noting that threshold dose relates to both general and specific causation. Recently, another BELO case, Ruffin v. BP Exploration & Production, Inc., addressed by the Fifth Circuit Court of Appeals on May 12, 2025, highlights how separating an expert’s general causation opinion from its impact on specific causation can complicate analysis.
