## Facts

- Multiple plaintiffs alleged that exposure to Monsanto’s glyphosate-based herbicides, including Roundup, caused them to develop Non-Hodgkin’s Lymphoma (NHL).
- The proceedings were consolidated in a federal multidistrict litigation in the Northern District of California.
- The case proceeded in a phased pretrial structure; the order addressed the early “general causation” phase.
- The general-causation question was whether glyphosate is capable of causing NHL at exposure levels people realistically experience.
- Plaintiffs offered expert testimony (including epidemiology, toxicology, and mechanistic evidence) to support general causation.
- Monsanto moved to exclude plaintiffs’ general-causation experts under Federal Rule of Evidence 702 and Daubert and separately sought summary judgment, arguing that without admissible expert evidence no reasonable jury could find general causation.

## Issues

1. Whether plaintiffs’ general-causation experts used reliable methods and reasoning under Federal Rule of Evidence 702 and Daubert such that their opinions on glyphosate causing NHL are admissible.
2. Whether, with the admissible expert evidence, a reasonable jury could find by a preponderance of the evidence that glyphosate can cause NHL at realistic exposure levels, precluding summary judgment.

## Decision

- The court largely denied Monsanto’s Daubert motions, permitting plaintiffs’ key general-causation experts to testify (with some limitations).
- The court denied Monsanto’s motions for summary judgment on general causation.
- The court held that, although it was a close question, plaintiffs had presented at least one admissible and reliable expert opinion such that a reasonable jury could find general causation.

## Legal Principles

- Under Federal Rule of Evidence 702 and Daubert, the court must act as gatekeeper to ensure expert testimony is grounded in sufficient data, reliable methods, and reliable application; it does not resolve which side’s scientific interpretation is correct.
- In a general-causation phase, plaintiffs must present at least one reliable expert opinion that the substance is capable of causing the disease at real-world exposure levels; absent admissible expert testimony, summary judgment is appropriate.
- A public-health “hazard” classification (including IARC’s “probably carcinogenic” designation) is relevant but does not, by itself, establish tort causation at real-world doses; litigation focuses on whether causation is more likely than not.
- Disputes about the interpretation of epidemiological, toxicological, and mechanistic data ordinarily go to weight and are tested through cross-examination and competing evidence, unless the expert’s methodology is so unreliable that exclusion is required.

## Conclusion

The court allowed plaintiffs’ general-causation experts to testify that glyphosate can cause NHL and, because admissible expert evidence created a triable causation question, denied Monsanto summary judgment and permitted the litigation to proceed beyond the general-causation phase.


In re Roundup Prods. Liab. Litig., 390 F. Supp. 3d 1102 (N.D. Cal. 2018)