## Facts

- Eight minor children and their parents alleged that maternal prenatal exposure to DuPont’s fungicide Benlate caused severe congenital defects.
- Plaintiffs alleged Benlate is a teratogen and that dermal exposure during pregnancy caused abnormal prenatal development.
- DuPont disputed causation and asserted a genetic explanation, particularly that one child’s defects were attributable to CHARGE syndrome.
- Updated genetic testing revealed a CHD7 gene mutation believed to cause CHARGE syndrome and understood to be genetic rather than externally induced.
- Plaintiffs offered three experts to prove specific causation:
  - A geneticist who, after the CHD7 result, revised his opinion to conclude the condition was CHARGE syndrome substantially caused by the mutation and stated he could not rule out Benlate because he was not a teratology/toxicology expert.
  - A toxicology/teratology physician who maintained Benlate caused or contributed to the injuries, including an interaction theory between Benlate and the genetic mutation, while acknowledging he was not a genetics expert and relied on the geneticist’s work.
  - An exposure expert who proposed to quantify dermal absorption and dose but conceded only a “working knowledge” of dermal absorption.
- DuPont moved to exclude the experts under Delaware Rule of Evidence 702 and Daubert and sought summary judgment based on the absence of admissible causation evidence.

## Issues

1. Whether plaintiffs’ proffered experts were qualified and used reliable, case-fitted methods sufficient for admissibility under Delaware Rule of Evidence 702 and Daubert.
2. Whether, after excluding inadmissible expert opinions, plaintiffs could present sufficient evidence of specific causation to survive summary judgment.

## Decision

- The court excluded key causation testimony from the toxicology/teratology expert as unreliable under Rule 702/Daubert.
- The court excluded the dermal absorption/exposure expert as not qualified to opine as an expert in dermal absorption, undermining other opinions that relied on his exposure conclusions.
- The court limited the geneticist’s testimony to his field and treated the CHD7 testing as strong objective support for a genetic cause.
- With no admissible expert evidence establishing Benlate as a substantial factor in causing the injuries, the court granted summary judgment for DuPont.

## Legal Principles

- Under Delaware Rule of Evidence 702 and Daubert, expert opinions must be based on sufficient qualifications and reliable methods, and must fit the facts of the case.
- A theory lacking peer review, general acceptance, or supporting data may be excluded as unreliable, particularly where it proposes a specific gene–chemical interaction without scientific support.
- Experts may not supply opinions outside their demonstrated expertise; cross-disciplinary assumptions may be excluded or restricted.
- When essential expert causation testimony is excluded in a toxic-tort case, summary judgment is proper if the plaintiff cannot prove specific causation with admissible evidence.
- Where objective genetic evidence provides a supported alternative cause, causation opinions that do not reliably account for that evidence may be excluded as speculative.

## Conclusion

The court applied Rule 702 and Daubert to exclude plaintiffs’ experts for lack of qualification and methodological reliability, then entered summary judgment for DuPont because plaintiffs lacked admissible expert proof that prenatal Benlate exposure was a substantial factor in causing the children’s birth defects.


Bowen v. E.I. Du Pont de Nemours & Co., 2005 WL 1952859 (Del. Super. Ct. June 23, 2005)