## Facts

- A control valve failure at Exxon Mobil’s Baton Rouge Chemical Plant caused sponge oil to leak and ignite on August 8, 1994; the fire continued until August 11, 1994.
- Smoke from the fire traveled southwest across the Mississippi River; Exxon conducted air monitoring during the incident.
- Numerous plaintiffs filed suits alleging personal injury, discomfort/annoyance, emotional distress and fear of future harm, and business/property losses.
- The actions were consolidated in federal court, and plaintiffs sought certification of a broad Rule 23(b)(3) damages class covering persons and entities in two Louisiana parishes who allegedly suffered legally cognizable damages and had not settled.
- The district court granted summary judgment on some claims, then denied class certification, finding Rule 23(b)(3) predominance and superiority were not met and Rule 23(a) typicality and adequacy were lacking.
- Plaintiffs obtained interlocutory review under Rule 23(f) and challenged the denial as an abuse of discretion.

## Issues

1. Whether common questions regarding the cause of the fire and Exxon’s alleged negligence predominated over individualized questions of exposure, specific causation, and damages under Rule 23(b)(3).
2. Whether a class action was a superior method to adjudicate the claims given manageability concerns and available alternatives.
3. Whether the proposed representatives satisfied Rule 23(a)’s typicality and adequacy requirements in light of heterogeneous claimed injuries and interests.

## Decision

- The Fifth Circuit affirmed the order denying class certification.
- The court held the district court did not abuse its discretion in finding predominance was not satisfied because individualized inquiries into exposure, causation, and damages outweighed common liability questions.
- The court held the district court did not abuse its discretion in concluding a class action was not superior given the need for claimant-by-claimant proof and resulting manageability problems.
- The court agreed that typicality and adequacy were not shown where class members asserted materially different injury types and could have divergent litigation objectives.

## Legal Principles

- Class certification rulings are reviewed for abuse of discretion; district courts have broad discretion to determine whether Rule 23’s requirements are met.
- Rule 23(b)(3) predominance is not established merely because liability questions are common; courts must evaluate whether individualized issues (especially exposure, specific causation, and damages) outweigh common ones.
- In mass-tort exposure cases, differences in location, degree and duration of exposure, medical and property circumstances, and damage theories often require individualized proof that defeats predominance.
- Rule 23(b)(3) superiority requires that class treatment be fair and efficient; when individualized determinations are extensive, class treatment may be inferior to consolidation, joinder, or other case-management approaches.
- Rule 23(a) typicality and adequacy may fail when proposed classes combine materially different injuries and remedies, creating potential intra-class conflicts and impairing representation.

## Conclusion

The Fifth Circuit upheld denial of a broad Rule 23(b)(3) class arising from a single refinery-fire event because individualized issues of exposure, causation, and damages, along with manageability and representation concerns, prevented certification.


Steering Committee v. Exxon Mobil Corp., 461 F.3d 598 (5th Cir. 2006)