Opinion of the Court
Delaval Inc., 476 U. S. 858, 864 (1986).
This is a maritime tort case. The plaintiffs allege that the defendant equipment manufacturers were negligent in failing to warn about the dangers of asbestos. “The general maritime law has recognized the tort of negligence for more than a century….” Norfolk Shipbuilding & Drydock Corp. v. Garris, 532 U. S. 811, 820 (2001); see also Kermarec v. Compagnie Generale Transatlantique, 358 U. S. 625, 631–632 (1959). Maritime law has likewise recognized common-law principles of products liability for decades. See East River S. S. Corp., 476 U. S., at 865.
In this negligence case, we must decide whether a manufacturer has a duty to warn when the manufacturer’s product requires later incorporation of a dangerous part—here, asbestos—in order for the integrated product to function as intended.
We start with basic tort-law principles. Tort law imposes “a duty to exercise reasonable care” on those whose conduct presents a risk of harm to others. 1 Restatement (Third) of Torts: Liability for Physical and Emotional Harm §7, p. 77 (2005). For the manufacturer of a product, the general duty of care includes a duty to warn when the manufacturer “knows or has reason to know” that its product “is or is likely to be dangerous for the use for which it is supplied” and the manufacturer “has no reason to believe” that the product’s users will realize that danger. 2 Restatement (Second) of Torts §388, p. 301 (1963–1964).
In tort cases, the federal and state courts have not reached consensus on how to apply that general tort-law “duty to warn” principle when the manufacturer’s product requires later incorporation of a dangerous part in order for the integrated product to function as intended. Three approaches have emerged.
The first approach is the more plaintiff-friendly foreseeability rule that the Third Circuit adopted in this case: A
