The following article appeared on August 26, 2026 on Bloomberg Law

On July 27, Johnson & Johnson agreed to a proposed $5.5 billion resolution of about 76,000 ovarian cancer talc claims across the federal multidistrict litigation and related state cases, conditioned on 95% claimant acceptance. J&J didn’t lose a trial to get there. It won an evidentiary fight over one question: whether plaintiffs could prove that talc caused any particular woman’s cancer.

Days earlier, Magistrate Judge Rukhsanah L. Singh had ordered plaintiffs to show why their claims shouldn’t be dismissed for inability to prove specific causation, after they withdrew their two lead causation experts. However framed, the largest mass tort in the country turned on attribution — the link between population-level risk and an individual plaintiff’s disease.

That question is no longer a talc problem. It is the central evidentiary contest across toxic tort, pharmaceutical, and climate litigation.

Two Layers

Tort law asks plaintiffs to prove that a substance can cause a disease, and that it caused this plaintiff’s disease. The burden is preponderance of the evidence, not beyond a reasonable doubt. Attribution is where it stops being easy. Plaintiffs build general causation through cohort studies, meta-analyses, and Bradford Hill analysis, then lean on the population association to carry specific causation. But those tools describe a group, not a patient.

The talc record shows the strain: The International Agency for Research on Cancer reclassified talc as a Group 2A probable human carcinogen in July 2024, and case-control studies found a 30% to 35% rise in ovarian cancer risk among frequent users, yet the largest pooled cohort analysis found no significant association. In a 658-page report in January 2026, retired Judge Freda Wolfson, sitting as special master, recommended that plaintiffs’ general-causation experts be allowed to testify.

General causation was never the weak point. Specific causation moved to a separate track, and that is where the experts withdrew rather than defend a method the literature doesn’t supply.

Rule 702 Shift

The December 2023 amendment to Federal Rule of Evidence 702 changed expert gatekeeping. Courts applying Daubert v. Merrell Dow Pharmaceuticals had sometimes confirmed a minimal reliability threshold and left weight to the jury. The amended rule requires the court to find — by a preponderance of the evidence — that an opinion reflects a reliable application of reliable methods. Judge Michael Shipp reopened the talc proceedings on that basis.

The change lands hardest in specific causation, where the question is forensic: whether this woman’s use caused her cancer given her exposure, genetics, age, and other risk factors. No epidemiological study answers that. When a court demands the method and none exists, the case doesn’t reach a jury. In the talc multidistrict litigation, that demand drove a proposed $5.5 billion resolution without a verdict.

The Climate Parallel

The same gap is heading for climate litigation. Attribution science can show that warming raised the probability of a harm across a region, but a damages suit still must tie specific losses to specific defendants.

State high courts have already split, with Colorado allowing Boulder’s claims and Maryland rejecting Baltimore’s, and the US Supreme Court will resolve it in Suncor Energy (U.S.A.) Inc. v. County Commissioners of Boulder County, on whether the Clean Air Act preempts state-law climate claims. The suits that survive will face the talc problem in a new setting: moving from population-scale models to quantified, defendant-specific damages.

Plaintiffs have a fair rejoinder. Differential etiology (the method of identifying a probable cause by systematically ruling out alternatives) has cleared Daubert in other mass torts, and causation is the jury’s to weigh once a reliable method is in evidence. The talc plaintiffs didn’t lose at trial. They settled after conceding the experts they had, which isn’t the same as proving the method can’t exist. The real question is whether an expert can show the method to a judge, not assert it to a jury.

Takeaways for Practitioners

For plaintiffs’ counsel, the discipline has to shift to the front of the case. Specific-causation methodology should be built and stress-tested before filing, not after discovery closes and a Daubert motion is pending. The expert who survives post-amendment scrutiny can name a validated framework for individual causation, apply it to the named plaintiff, account for competing risks, and say plainly what the literature can’t establish.

A differential-etiology opinion that rules in the product without ruling out other causes won’t clear the gate. Strong general-causation witnesses remain necessary but no longer sufficient, and a roster built only on population epidemiology carries hidden settlement risk. One order to show cause on specific causation can collapse a firm’s leverage across an entire inventory, as the talc plaintiffs learned. The same exposure runs through PFAS, glyphosate, microplastics, and opioid claims.

For defense counsel, the talc resolution is a template. The winning move wasn’t a broadside against the plaintiffs’ science but a narrow strike at the seam between general and specific causation.

Concede the epidemiology where it’s settled, decline to relitigate general causation the court has accepted, and aim the Rule 702 challenge at the absence of a reliable method for individual attribution, letting the burden the amended rule puts on the proponent do the work. Overreaching on general causation — as J&J’s early junk-science framing did before the special master’s report — spends credibility on the one issue a defendant is likely to lose.

For courts, the task is to hold a line between two things that look alike. An attribution failure isn’t proof that the underlying science is fraudulent; it’s a limit on what population data can answer about one patient. The gatekeeping question is narrow: Has the proponent shown a reliable method for moving from group risk to this plaintiff, by a preponderance of the evidence?

Attribution is now the question that decides these cases, and the courts that handle it carefully will write the doctrine the rest follow.

This article does not necessarily reflect the opinion of Bloomberg Industry Group Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.    Reproduced with permission. Published Aug. 26, 2026. Copyright 2026 Bloomberg Industry Group 800-372-1033. For further use please visit https://www.bloombergindustry.com/copyright-and-usage-guidelines-copyright/

Author Information

Gregg Goldfarb is an attorney in Florida whose practice focuses on plaintiff-side mass torts, environmental litigation, and corporate accountability.