## Facts

- Misco, Inc. and the Union were parties to a collective-bargaining agreement (CBA) providing for binding arbitration of grievances involving interpretation or application of the agreement.
- The CBA reserved to management the right to enforce disciplinary rules, including discharge for “possession or use of controlled substances on company property.”
- A union-represented machine operator, Cooper, worked the night shift operating hazardous equipment.
- Police found Cooper and others in a smoke-filled car in Misco’s parking lot; marijuana smoke was present and a lighted marijuana cigarette was in the front-seat ashtray.
- Police also found marijuana remnants in Cooper’s own car parked on the lot, but Misco did not know of that evidence at the time it discharged Cooper.
- Misco discharged Cooper for violating the controlled-substances rule; the Union filed a grievance contesting whether Misco had “just cause” and seeking a remedy.
- The arbitrator excluded evidence of the marijuana remnants from Cooper’s car because Misco did not rely on it when discharging him, found the remaining evidence insufficient to prove a rule violation, and ordered reinstatement.
- A federal district court vacated the award, and the Fifth Circuit affirmed, reasoning that reinstatement violated public policy against operating dangerous machinery under the influence of drugs and that the excluded evidence established just cause.

## Issues

1. Whether the lower courts exceeded the limited scope of review by reexamining the merits of the arbitrator’s factual findings, evidentiary rulings, and “just cause” determination.
2. Whether enforcing the reinstatement award was barred by a “well defined and dominant” public policy requiring vacatur.

## Decision

- The Supreme Court reversed the Fifth Circuit and directed enforcement of the arbitration award.
- The Court held that, absent fraud or dishonesty, reviewing courts may not reconsider the merits of a labor-arbitration award or substitute their judgment for the arbitrator’s view of the facts and the contract.
- The Court held that the asserted public policy was too generalized and not shown to be an explicit, well-defined, and dominant policy grounded in laws and legal precedents.
- The Court rejected the lower courts’ safety-based inferences about Cooper’s on-the-job drug use as improper judicial factfinding inconsistent with deferential review.

## Legal Principles

- Judicial review of labor-arbitration awards under a CBA is highly limited; courts generally may not reweigh evidence, revisit credibility or factual determinations, or correct arguable arbitral errors.
- A labor-arbitration award must be enforced if it “draws its essence” from the CBA and does not merely reflect the arbitrator’s personal notions of industrial justice.
- The public policy exception is narrow: a court may refuse enforcement only when the award would violate an explicit, well-defined, and dominant public policy ascertainable from positive law and controlling legal precedent, not from general safety concerns or broad public interests.
- Courts may not set aside an award based on speculation or assumptions that require factual findings the arbitrator did not make.

## Conclusion

The Court required enforcement of the reinstatement award, holding that the lower courts impermissibly retried the grievance and invoked an insufficiently concrete public policy; labor-arbitration outcomes must stand when grounded in the CBA and not in conflict with a clearly established legal policy.


United Paperworkers Int’l Union, AFL-CIO v. Misco, Inc., 484 U.S. 29 (1987)