## Facts

- Chester Laster worked at a Philip-Carey/Celotex plant from about 1929 to 1970 and allegedly inhaled asbestos dust and fibers at work.
- He later developed pleural mesothelioma.
- Before trial, plaintiffs moved under Federal Rule of Evidence 201 for judicial notice that (1) asbestosis is caused by inhalation of asbestos dust and fibers and (2) mesothelioma is caused by inhalation of asbestos dust and fibers.
- Plaintiffs proposed jury instructions stating, in categorical terms, that inhalation of asbestos fibers and dust “is the cause” of these diseases.
- Defendants opposed, arguing the proposed facts were overstated and implied asbestos exposure causes disease regardless of fiber characteristics, dose, and duration of exposure.

## Issues

1. Whether Rule 201 permits judicial notice, as adjudicative facts, that asbestosis and mesothelioma are caused by inhalation of asbestos dust and fibers.
2. Whether the requested causation propositions were “not subject to reasonable dispute” because they were generally known in the court’s jurisdiction or readily determinable from unimpeachable sources.

## Decision

- The court denied both motions for judicial notice.
- The court treated the requested propositions about disease causation as adjudicative facts governed by Federal Rule of Evidence 201.
- The court found the propositions were not generally known within the court’s territorial jurisdiction.
- The court also found the propositions were not capable of accurate and ready determination from sources whose accuracy could not reasonably be questioned, given disputes about variables affecting causation and the existence of other suggested causes.
- The court concluded that broad, categorical causation statements would not meaningfully narrow the expert proof required on whether asbestos exposure caused the plaintiff’s condition under the particular exposure circumstances.

## Legal Principles

- Federal Rule of Evidence 201 governs judicial notice of adjudicative facts in federal court.
- A fact may be judicially noticed only if it is not subject to reasonable dispute because it is (1) generally known within the trial court’s territorial jurisdiction or (2) capable of accurate and ready determination from sources whose accuracy cannot reasonably be questioned.
- Complex medical causation propositions in toxic-tort litigation generally are not appropriate for judicial notice when phrased categorically and when causation depends on contested variables (including dose, duration, fiber characteristics, and alternative causes).
- Judicial notice cannot be used to replace the parties’ right to present and challenge expert evidence on disputed causation questions tied to a plaintiff’s specific exposure and medical condition.

## Conclusion

The court refused to take judicial notice that inhalation of asbestos dust and fibers causes asbestosis or mesothelioma because the proposed causation statements were framed too broadly and remained reasonably disputable under Rule 201, leaving medical causation to be proved through expert testimony at trial.


Laster v. Celotex Corp., 587 F. Supp. 542 (S.D. Ohio 1984)