Daubert Meets Res Ipsa: Seventh Circuit Rejects Twin Theories of Liability in Uniform Defect Suit

The Seventh Circuit affirmed the Northern District of Illinois’s decision granting summary judgment for American Airlines and a uniform manufacturer in a suit brought by 74 airline employees alleging the airline’s uniforms caused rashes, allergic reactions, and other symptoms. Zurbriggen v. Twin Hill Acquisition, Inc., 178 F.4th 1081, 1091 (7th Cir. 2026).

The district court granted summary judgment after excluding plaintiffs’ two causation experts, a toxicologist and a textile chemist, because neither could reliably opine that the uniforms were manufactured with chemicals that caused plaintiffs’ symptoms. The court cited analytical failures, including the absence of a “plausible theory of exposure, failure to identify a toxic chemical, lack of theoretical or empirical support, and unjustified reliance on complaint data and [defendant] testing,” as well as unsupported assumptions that the detected chemicals were introduced during garment manufacturing and served “no legitimate” manufacturing purpose. Zurbriggen v. Twin Hill Acquisition Co., Inc., 2025 WL 1092973, at *21 (N.D. Ill. Apr. 11, 2025). In a footnote, the district court rejected plaintiffs’ attempt to invoke res ipsa loquitur to infer a defect in the airline uniforms based solely on plaintiffs’ alleged symptoms. Id. at *21 n.19.

On appeal, the Seventh Circuit adopted the district court’s “first-rate” Daubert opinion and affirmed exclusion of both experts. Zurbriggen, 178 F.4th at 1084, 1088. It also agreed with the district court’s rejection of plaintiffs’ “res ipsa-style theories.” Id. at 1091. The court held that plaintiffs could not use res ipsa to bypass their burden to establish the elements of their strict liability claim: the uniforms did not “fail to perform as expected” because they “did not break, collapse, or malfunction.” Id. at 1090. A “defect” in the uniforms was also “not the most obvious answer” for the “various reactions” plaintiffs experienced. Id. at 1091. Res ipsa likewise did not support negligence because the manufacturer “had long since relinquished control over” the uniforms by the time they were tested, as they had been “shipped across the world by multiple intermediaries.” Id.