Monsanto v. Durnell · ¶148

There is another reason that the right outcome in today’s case differs from Riegel: Riegel did not involve “parallel claims.” 552 U. S., at 330. The litigation in Riegel proceeded on the assumption that the medical device “violated state tort law notwithstanding compliance with the relevant federal requirements.” Ibid. So this Court had no occasion to consider whether there was an applicable federal requirement, apart from the FDA’s premarket approval process, that might be equivalent to the plaintiffs’ tort claim. Here, by contrast, it is precisely because FIFRA’s misbranding prohibition parallels Missouri’s failure-towarn claim that Durnell’s claim is not preempted.

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