[JURIST] The US Supreme Court [official website; JURIST news archive] on Wednesday unanimously reversed [opinion, PDF] a California appeals court ruling [opinion, PDF] in Williamson v. Mazda Motors of America [docket], finding that a federal minimum safety standard [text] does not preempt state tort actions. The court held that compliance with Federal Motor Vehicle Safety Standard No. 208 [text], which requires automobile manufacturers to install lap and shoulder seat belt assemblies only for a vehicle’s outboard seating and permits lap-only seat belts at the inboard seating, does not bar a state tort action alleging that the manufacturer should have installed lap and shoulder restraints in the latter seating positions. Writing for the unanimous court, Justice Stephen Breyer stated that the regulations represent minimum standards and that they do not exempt manufacturers from liability:

The more important reason why [the US Department of Transportation] did not require lap-and-shoulder belts for rear inner seats was that it thought that this requirement would not be cost-effective. … But that fact – the fact that DOT made a negative judgment about cost effectiveness – cannot by itself show that DOT sought to forbid common law tort suits in which a judge or jury might reach a different conclusion.

Per the court, preemption would only have been proper had the “significant objective” of the regulation been to provide manufacturers with a choice between seat belt types.

The court heard arguments [oral arguments transcript, PDF; JURIST report] on the matter in November, during which time counsel for the petitioners, joined by the US government as amicus curiae, argued that “[t]he claim is not preempted, because it is perfectly consistent with and would not frustrate the objectives of the operative 1989 version of Standard 208 governing Type 2 seat belts in rear seats.” The petitioners also claimed that Mazda [corporate website] had a duty to warn of safety risks associated with lap-only seat belts under Wyeth v. Levine [opinion, PDF; JURIST report], in which the Supreme Court ruled that federal approval of labels giving warnings about effects of drugs does not bar lawsuits under state law claiming inadequate warnings of a health risk. Counsel for respondents countered that the claim should be preempted because the federal government did not merely provide a minimum standard, but left the option to the manufacturer because of safety trade-offs for each type of seat belt. The court granted certiorari [cert. petition, PDF; JURIST report] in May.