## Facts

- Judith Sindell alleged she developed a rare cancer as a result of in utero exposure to diethylstilbestrol (DES), a synthetic estrogen prescribed to pregnant women to prevent miscarriage.
- DES was marketed from the late 1940s through the early 1970s; it was produced by many manufacturers using the same formula.
- The alleged injury had a long latency period, and the DES pills were chemically identical and interchangeable, making it practically impossible to identify which manufacturer produced the specific pills ingested by Sindell’s mother.
- Sindell sued multiple DES manufacturers on negligence and strict products liability theories, alleging inadequate testing and warnings and industry-wide reliance on shared testing and marketing practices.
- The trial court sustained defendants’ demurrers and dismissed the action for failure to plead causation because Sindell could not identify the specific manufacturer responsible.
- The California Supreme Court reviewed whether the action could proceed under a modified causation approach.

## Issues

1. Whether a plaintiff injured by a fungible product may proceed against multiple manufacturers without identifying the specific maker of the injury-causing dose.
2. Whether causation may be established through a rebuttable presumption and liability apportioned according to each defendant’s share of the relevant market.
3. What limits and prerequisites must be shown before shifting the burden to defendants to disprove causation.

## Decision

- The court reversed the judgment of dismissal.
- It held that, for a fungible product like DES, a plaintiff who cannot identify the specific manufacturer despite reasonable efforts may recover from joined manufacturers according to their respective market shares.
- The court adopted a market share liability approach: each defendant is liable for the proportion of the judgment represented by its share of the relevant DES market, unless it proves it could not have made or supplied the product that caused the injury.
- The court rejected imposing joint liability under alternative liability principles because not all potentially responsible manufacturers were necessarily joined.
- The court also rejected broad enterprise/industry-wide liability as insufficiently tied to each defendant’s connection to the risk.
- A dissent argued the rule improperly dispensed with traditional causation, risked imposing liability on noncausal defendants, and raised administrability and separation-of-powers concerns.

## Legal Principles

- In products cases involving a chemically fungible product and latent injury where identification of the specific manufacturer is not feasible despite reasonable diligence, a plaintiff may satisfy causation through a rebuttable, market-based presumption.
- A prerequisite is that defendants joined represent a substantial share of the relevant market for the product during the time and place of exposure.
- Liability is several and apportioned: each defendant is responsible for the percentage of damages corresponding to its market share, reflecting the probabilistic likelihood it supplied the injury-causing product.
- The burden shifts to each defendant to exonerate itself by showing it could not have made or supplied the injury-causing product (for example, by proving it did not sell in the relevant area or did not manufacture during the relevant time).
- The doctrine is limited to contexts where fungibility and proof barriers make traditional product identification an unreasonable condition for recovery and where market shares can be estimated with sufficient reliability.

## Conclusion

The court permitted DES plaintiffs who cannot identify the specific manufacturer to proceed by using market share liability, shifting causation-related proof burdens and apportioning damages according to each defendant’s contribution to the relevant DES market, subject to defendants’ opportunity to prove noninvolvement.


Sindell v. Abbott Laboratories, 26 Cal. 3d 588, 607 P.2d 924 (Cal. 1980)