The Supreme Court of New Hampshire declined to recognize medical monitoring as a remedy or cause of action for plaintiffs who claim exposure to toxic substances. The court based its reasoning on New Hampshire common law and public policy, explaining that an increased risk of injury is insufficient to state a claim for medical monitoring as a remedy or cause of action. See Brown v. Saint-Gobain Performance Plastics Corp., No. 2022-0132, 2023 WL 2577257 (N.H. Mar. 21, 2023).


The plaintiffs, who live or have lived near Merrimack, New Hampshire, brought a putative class action based in tort alleging that the defendants released perfluorooctanoic acid (PFOA), a type of per- and polyfluoroalkyl substances (PFAS), from a facility in Merrimack. As a result of their exposure to PFOA, the plaintiffs allege that they have an increased risk of illness, requiring a medical monitoring program for the detection of such illness.

The law on medical monitoring varies from state to state. Even in states that recognize medical monitoring as a remedy or cause of action, courts impose different requirements. In particular, courts diverge on whether a plaintiff must show a present physical injury that was caused by a defendant or whether an increased risk of injury is sufficient.

Here, this case was removed to the United States District Court for the District of New Hampshire, and the federal court found no controlling precedent from the New Hampshire Supreme Court on medical monitoring. As a result, the federal court certified questions to the New Hampshire Supreme Court, asking whether the state recognizes a claim for the costs of medical monitoring as a remedy or cause of action in the context of plaintiffs who were tortiously exposed to a toxic substance, and if so, what are the particular requirements and elements in New Hampshire.

Court’s Decision

In rejecting medical monitoring as a remedy or cause of action, the court emphasized New Hampshire common law and public policy. First, the court found decisions from other jurisdictions recognizing medical monitoring claims unpersuasive. Instead, the court followed New Hampshire precedent, ruling that the possibility of injury is not an injury itself.

Second, while the plaintiffs argued that public policy favors medical monitoring, the defendants noted that the New Hampshire legislature recently failed to override the governor’s veto of a bill that would have established a statutory cause of action for medical monitoring. The court reasoned that this recent legislative action reflects the public policy of New Hampshire, confirming that the state’s common law has not been superseded by statute on this issue.

Looking Forward

The court’s ruling confirms that New Hampshire does not recognize medical monitoring claims. This is expected to impact litigation relating to PFAS and other emerging torts, where causation is unclear and plaintiffs must pursue novel theories of recovery, such as medical monitoring. As litigation on PFAS continues, plaintiffs are expected to test the limits of medical monitoring in other jurisdictions as well.