## Facts

- Oxygenated Fuels Association, Inc. (OFA), a trade association for producers of methyl tertiary-butyl ether (MTBE), challenged California’s decision to phase out and ban MTBE in gasoline.
- MTBE is an oxygenate used in reformulated gasoline to reduce vehicle emissions and help meet Clean Air Act (CAA) requirements in certain areas.
- California adopted the MTBE ban based primarily on groundwater contamination and public-health concerns rather than motor-vehicle emission control.
- OFA alleged the ban interfered with the federal reformulated gasoline program, which requires specified oxygen content, and argued the ban was effectively fuel regulation for emission-control purposes.
- OFA sued the Governor of California and the Chair of the California Air Resources Board (CARB) to enjoin enforcement, alleging federal preemption under the CAA.
- The federal district court dismissed the complaint on the defendants’ motion, and OFA appealed.

## Issues

1. Whether California’s MTBE ban is expressly preempted by the CAA’s fuel and fuel-additive preemption provision, 42 U.S.C. § 7545(c)(4), in light of California’s statutory exemption in § 7545(c)(4)(B).
2. Whether the MTBE ban is impliedly preempted because it conflicts with the purposes and objectives of the CAA, including the reformulated gasoline and oxygen-content requirements.

## Decision

- The Ninth Circuit affirmed the dismissal of OFA’s suit.
- The court held California’s MTBE ban was not preempted by the CAA.
- The court reasoned that Congress preserved substantial state authority to legislate for public health and safety and that the ban did not conflict with federal objectives.
- The court concluded California could satisfy federal reformulated gasoline requirements through alternative oxygenates, so the ban did not obstruct attainment of federal air-quality goals.

## Legal Principles

- Preemption analysis under the CAA requires attention to congressional design preserving state authority, including traditional police-power regulation addressing public health and safety.
- A state measure affecting fuel composition is not automatically preempted merely because the CAA contains an express fuel-preemption clause; conflict with federal objectives remains central where state authority is preserved.
- Conflict (obstacle) preemption applies only when state law stands as an obstacle to accomplishing Congress’s purposes; no conflict exists where compliance with federal requirements remains feasible through lawful alternatives.
- Under the CAA’s cooperative federalism structure, states may adopt environmental measures aimed at non-air harms (such as water contamination) when those measures do not frustrate federal air-quality programs.

## Conclusion

The Ninth Circuit upheld California’s MTBE ban against an express and implied preemption challenge, concluding the ban was a permissible exercise of state public-health authority targeting groundwater contamination and did not obstruct the Clean Air Act’s air-quality objectives because alternative oxygenates allowed continued compliance with federal reformulated gasoline requirements.


Oxygenated Fuels Ass'n, Inc. v. Davis, 331 F.3d 665 (9th Cir. 2003)