Georgia Courts Must Follow Federal Standard for Toxic Tort Experts, Appeals Court Rules

The Georgia Court of Appeals issued a decision on October 31, 2025, addressing the reliability and admissibility of expert testimony on general causation in toxic tort cases in Georgia. See Sterigenics US LLC. Mutz, No. A25A1377, 2025 WL 3041770 (Ga. Ct. App. Oct. 31, 2025) (the “Mutz” decision). Under this new decision, Georgia trial courts evaluating experts pursuant to O.C.G.A. § 24-7-702 (“Rule 702”) must apply the federal two-tiered classification standard established 20 years ago by the Eleventh Circuit Court of Appeals in McClain v. Metabolife Intl., Inc., 401 F.3d 1233 (11th Cir. 2005).

Georgia’s Expert Testimony Statute:

Causation is an essential element in any toxic tort claim brought in Georgia. See Ga. Power Co. v. Campbell, 360 Ga. App. 422, 861 S.E.2d 255 (2021). Proof of causation in a toxic tort case often requires reliable expert testimony. Id. To determine whether expert testimony shall be admissible, Georgia courts look at Rule 702–Georgia’s expert testimony statute. This statute outlines who qualifies as an expert to testify:

1. 1. The expert’s scientific or specialized knowledge will help understand the evidence or clarify a fact in issue;
   2. The opinion is based on sufficient data;
   3. The testimony is the product of reliable principles and methods; and
   4. The expert has reliably applied these methods to the facts of the subject case.

The Georgia Court of Appeals’ recent decision in Mutz analyzing the expert testimony statute explains that Georgia Rule 702 is materially analogous to the Federal Rule 702, and as a result, Georgia courts will look at “‘federal appellate precedent until a Georgia appellate court decides the issue,’” Sterigenics, 2025 WL 2041770 at *2. This decision is the first Georgia appellate court opinion to directly address the reliability requirement for general causation in toxic tort cases under Rule 702.

The Federal McClain Standard:

In McClain, the Eleventh Circuit created a classification system and explained that toxic tort cases are generally divisible into two categories:

1. 1. Cases where the medical community generally recognizes the toxicity of the chemical; and
   2. Cases where the medical community does not generally recognize the chemical as toxic and causing the specific injury the plaintiff alleges.

The Eleventh Circuit explained that cases that fall within the first category should rather focus on specific causation. On the other hand, litigants who fall within the second category must establish general causation through reliable expert testimony under a more stringent standard.

The Georgia Standard Following McClain:

The Mutz case arose from several consolidated toxic tort lawsuits in the State Court of Cobb County, Georgia. As the case proceeded to expert discovery before the trial court, the plaintiffs produced three experts to address general causation. The trial court ultimately excluded the testimony of two of the plaintiff’s three experts.

While the trial court’s ruling acknowledged the two-part categorical system presented in McClain, the trial court offered its own modified category beyond those set forth under the McClain rule–either those where the medical community recognizes the toxicity of a chemical or those where it does not. The Plaintiffs pursued an appeal to challenge the exclusion of two experts while a concurrent appeal addressed the trial court’s decision to admit the testimony of the third expert.

The Georgia Court of Appeals found that the trial court improperly created a third category, and therefore, abused its discretion by deviating from the McClain two-tiered framework. The matter has been remanded for the trial court to consider the expert witnesses in dispute under the Eleventh Circuit’s McClain standard only.

Potential Impacts: 

The Georgia Court of Appeals ruling in Mutz will impact pending and future toxic tort cases in Georgia concerning the admissibility of expert testimony on general causation. Georgia trial courts must now follow the Eleventh Circuit’s two-tiered classification framework. The first-ever Georgia appellate opinion directly addressing expert opinions in toxic tort cases under Rule 702 provides a uniform standard to Georgia litigants engaged in toxic tort disputes.