## Facts

- Huron Portland Cement Co., a Michigan corporation, operated ships transporting cement in interstate commerce on the Great Lakes.
- Detroit enforced its Smoke Abatement Code against two of Huron’s vessels while docked in the Port of Detroit.
- The vessels used hand-fired Scotch marine boilers that had to remain fired during loading and unloading to operate onboard machinery.
- During periodic cleaning of the fires, the ships emitted smoke exceeding the ordinance’s density and duration limits.
- Compliance would have required structural alterations to the vessels’ equipment.
- Detroit initiated criminal prosecutions for ordinance violations; Huron sought a state-court injunction to stop prosecutions and prevent enforcement except for smoke caused by improper firing.
- Michigan courts denied injunctive relief, and the Michigan Supreme Court affirmed; the U.S. Supreme Court granted review.

## Issues

1. Whether federal inspection and licensing of vessels operating in interstate commerce preempted Detroit’s application of its smoke ordinance to federally licensed ships.
2. Whether applying Detroit’s smoke ordinance to Huron’s vessels imposed an unconstitutional burden on interstate commerce under the Commerce Clause.

## Decision

- The Supreme Court affirmed the Michigan Supreme Court.
- Federal vessel inspection and licensing laws did not preempt Detroit’s smoke ordinance as applied to Huron’s ships.
- The ordinance did not directly conflict with federal licensing or invalidate the federal permission to operate.
- The ordinance, as applied, did not impose an undue burden on interstate commerce.

## Legal Principles

- Federal regulation and licensing aimed at navigational safety do not, without a direct conflict, displace non-discriminatory local police-power measures aimed at public health and cleanliness.
- A generally applicable local health regulation may be enforced against instrumentalities of interstate commerce when it neither discriminates against interstate commerce nor frustrates a federal objective.
- A federal license to operate does not confer immunity from neutral local requirements governing conduct within the locality.
- Under the Commerce Clause, a neutral regulation serving substantial local health interests will be upheld absent an undue burden, especially where there is no showing of conflicting local regulatory schemes.

## Conclusion

Detroit could enforce its Smoke Abatement Code against federally licensed interstate vessels while docked in the city because the ordinance served local public health aims, did not conflict with federal inspection and licensing requirements, and did not impose an undue burden on interstate commerce.


Huron Portland Cement Co. v. City of Detroit, 362 U.S. 440 (1960)