The modern e-cigarette litigation cycle is in a mature phase. JUUL Labs settled its largest lawsuit for $462 million in 2023, and the multidistrict litigation (MDL 3016) in the Northern District of California has continued to produce discovery that shapes individual case strategy nationwide. At the same time, a federal appellate circuit split on FDA regulatory authority, decided in August 2026, has introduced new preemption arguments that defense counsel will deploy in pending cases. Plaintiff practitioners entering this litigation need a clear theory of the case, a command of the causation science, and a precise understanding of where the regulatory preemption defense succeeds and where it fails.
The Defect Theories
E-cigarette litigation draws on three distinct defect theories, each supported by different categories of evidence:
- Design defect. The core design-defect claim against JUUL and similar products is that the nicotine salt formulation, which delivers nicotine at concentrations significantly higher than prior-generation e-cigarettes, was unreasonably dangerous given the foreseeable population of users. Earlier pod-based e-cigarettes used freebase nicotine, which is harsh at high concentrations and self-limiting. Nicotine salt formulations are smooth at high concentrations, masking the user's ability to regulate intake. The consumer-expectation test, applicable in California and other jurisdictions, supports this theory: an ordinary user does not expect that a product marketed as a smoking-cessation device or as less harmful than cigarettes will deliver nicotine at levels associated with rapid physiological dependence.
- Warning defect. The failure-to-warn theory focuses on what the manufacturer knew about addiction rates and health risks and when it knew it, compared to the warnings actually placed on its products. Internal corporate documents produced in the JUUL MDL showed that the company conducted consumer research demonstrating rapid nicotine dependence, and that marketing programs specifically targeted young adults and, in some instances, minors, while warnings were inadequate to convey the addiction risk actually associated with the products. The heeding presumption, where available, shifts the burden to the manufacturer to rebut the inference that an adequate warning would have been followed.
- Manufacturing defect. In specific device categories, including defective pods, faulty heating elements, and battery failures, individual manufacturing defect claims exist separate from the systemic design and warning theories. These claims require chain-of-custody evidence connecting the specific failed unit to the manufacturer's production run.
Causation: The Addiction Science
Causation in nicotine addiction cases requires establishing that the specific product caused or substantially contributed to the plaintiff's physiological dependence and the resulting health consequences. The evidence framework includes:
- Epidemiological and toxicological foundation. Nicotine's pharmacology and its addiction mechanism are well-established. Expert testimony from a toxicologist or addiction medicine specialist is needed to bridge from that general scientific consensus to the plaintiff's specific use pattern, nicotine exposure, and resulting dependence.
- Product-specific nicotine delivery evidence. Studies comparing nicotine delivery from JUUL pods to traditional cigarettes support the claim that the product delivers supra-cigarette-level nicotine in patterns specifically associated with rapid addiction. This evidence distinguishes the product from the baseline harm of tobacco use generally.
- Medical causation for secondary injuries. Where the plaintiff suffered cardiovascular, pulmonary, or other health consequences attributable to vaping, a treating physician or specialist must connect those outcomes to the vaping exposure and distinguish them from any baseline risk from prior tobacco use.
The Youth Marketing Evidence
One of the most important categories of MDL discovery for individual cases is the internal marketing evidence showing that the companies either specifically targeted youth consumers or were aware that their products were achieving significant market penetration among minors and did not meaningfully act to prevent it. This evidence supports both the punitive damages narrative and the failure-to-warn theory: a manufacturer that designed marketing to appeal to a population it knew was at heightened addiction risk while maintaining inadequate warnings cannot claim it acted reasonably. Subpoena the company's market research data, agency communications, and internal compliance memoranda in individual cases where discovery is still open.
Preemption After the Circuit Split
Defense counsel in e-cigarette cases has increasingly deployed preemption arguments based on the Family Smoking Prevention and Tobacco Control Act. The Act expressly preempts state requirements that are "different from or in addition to" federal requirements, and impliedly preempts some state-law claims that would conflict with FDA's regulatory authority over tobacco products. The Ninth Circuit's August 2026 ruling upholding FDA's comparative-efficacy standard strengthens preemption arguments in cases filed in the Ninth Circuit, while the Fifth Circuit's contrary ruling in NicQuid LLC v. FDA weakens those arguments in the Fifth Circuit's geographic footprint. The practical consequence is that preemption analysis in e-cigarette cases is now circuit-specific. A case filed in a Texas federal court and one filed in a California federal court face different preemption environments. The implications of the circuit split for product liability practitioners are discussed at lawyerstrend.com/category/case-law-settlements.
MDL Posture and Individual Case Strategy
MDL 3016 has generated substantial common benefit work, and cases consolidated into the MDL benefit from that discovery record. Cases filed directly in federal district court outside the MDL, or in state court, can access the MDL's produced discovery through public filings and cooperative arrangements where applicable. Counsel entering this litigation for the first time should obtain and review the MDL's case management orders and key expert reports before developing their individual case theory.
The broader product liability framework, including defect theory development, chain of custody, and expert reconstruction strategy, is at lawyerstrend.com/category/product-liability. For fatal vaping-related cases involving minors or young adults, wrongful-death damages resources are at lawyerstrend.com/category/wrongful-death.