In this consolidated appeal,
1
we address a question of federal preemption: whether,
*575
based on Medtronic’s compliance with the Food and Drug Administration’s (“FDA”) rigorous premarket approval procedure (“PMA”), the plaintiffs’ Texas common law products liability tort claims are preempted by 21 U.S.C. § 360k, the Medical Devices Amendments (“MDA”) to the Food, Drug, and Cosmetic Act (“FDCA”). We have addressed this issue before. In
Stamps v. Collagen Corp.,
I
Billye Jeanne Martin and Libra Salazar each claim that they were injured by Med-tronic’s defective pacemaker (Model 4004). They allege that the pacemaker contained a defective “ventricular lead,” the wire that carries current into the heart muscle. Their product liability claims include negligence, gross negligence, strict liability, breach of warranty, and violation of the Texas Deceptive Trade Practices Act; all claims are based on alleged deficiencies in the safety and effectiveness of the design, manufacturing process, warnings, and labeling of the lead.
The district court initially granted Med-tronic’s motion for summary judgment only in part, finding that the MDA preempted Salazar’s and Martin’s design, manufacturing process, and warning claims. The district court reasoned that in all these areas, the FDA, through its PMA procedure, 2 had approved Medtronic’s product. The district court, however, denied summary judgment on the plaintiffs’ claims that Medtronic had deviated from FDA requirements. Following further discovery, Medtronic renewed its summary judgment motion. The district court then granted the renewed motion, finding that appellants failed to produce evidence of alleged deviations, and entered judgment dismissing each complaint. These appeals, now consolidated, present the single issue of whether the FDA’s PMA procedure preempts the state law tort claims.
II
We begin our consideration of this question of preemption by making a few preliminary observations that serve to place in context the even more precise issue before
*576
us — to what extent is our case today decided by precedents of this court
and the
Supreme Court. The MDA classifies medical devices into three categories based on the degree of risk they pose to the public. Class I devices pose little or no risk to public health and are subject only to general controls on manufacturing. Class II devices are potentially more harmful and may be subject to regulations and product specifications. Class III devices, the most strictly regulated, are “[djevices that either ‘presenft] a potential unreasonable risk of illness or injury,’ or which are ‘purported or represented to be for a use in supporting or sustaining human life or for a use which is of substantial importance in preventing impairment of human health.’ ”
Lohr,
A pacemaker is classified as a “Class III” medical device. As such, it must undergo an indisputably thorough, rigorous, and costly premarket review (some 1,200 FDA man-hours at hundreds of thousands of dollars in cost) by the FDA. Under this PMA process, the manufacturer must give the FDA a “reasonable assurance” that the product is safe and effective. Although this term does not sound excessively demanding, the PMA process is rigorous. It requires manufacturers to submit detailed information regarding the safety and efficacy of their devices. This includes, among other things, full reports of all information that is known by the applicant, samples of both labeling and the device itself, and a full description of the methods and facilities used for manufacturing and installation of the device.
See
21 U.S.C. § 360e(e)(l) (describing the components of a PMA application). The FDA then reviews the application, spending an average of 1,200 hours on each submission before granting marketing approval. The statutory basis for this process, and its exceptions, are set forth at length in
Lohr,
It is central to our resolution of this appeal that we have held that § 360k preempts these state products liability claims when the device manufacturer complies with the FDA’s PMA process.
See Stamps,
But yet there is a twist. After
Stamps,
the Supreme Court considered the scope of MDA preemption of state law claims in the “ § 510(k) notification” process,
3
an exception to the far more demanding PMA review process.
See Lohr,
Lohr,
however, is highly relevant to this appeal because it considered in some detail the preemption statute that is applicable both to the § 510(k) process and the PMA process. Notwithstanding its relevance, the Supreme Court decision must be more than merely illuminating with respect to the case before us, because a panel of this court can only overrule a prior panel decision if “such overruling is unequivocally directed by controlling Supreme Court precedent.”
United States v. Zuniga-Salinas,
A
To resolve the impact of Lohr on our precedent in Stamps, we begin by setting out the relevant statutory and regulatory language that we must consider. Section 360k(a) (“General Rule”) is the preemption provision of the MDA governing the extent to which the MDA preempts state law. It applies both to situations arising under the § 510(k) process and the PMA process. It states:
[N]o State or political subdivision of a State may establish or continue in effect with respect to a device intended for human use any requirement—
(1) which is different from, or in addition to, any requirement applicable under this chapter to the device, and
(2) which relates to the safety or effectiveness of the device or to any other matter included in a requirement applicable to the device under this chapter.
21 U.S.C. § 360k(a). The FDA has promulgated regulations interpreting § 360k, which state:
State or local requirements are preempted only when the Food and Drug Administration has established specific counterpart regulations or there are other specific requirements applicable to a particular device under the act, thereby making any existing divergent State or local requirements applicable to the device different from, or in addition to, the specific [FDA] requirements.
21 C.F.R. § 808.1(d).
B
With both the statute and the regulations in mind, we turn to consider the intervening Supreme Court decision,
Medtronic Inc. v. Lohr,
The facts underlying the plaintiffs’ claims in
Lohr
are similar to the facts in our case: Lohr and her husband sued on state law claims over a defective lead in a pacemaker. Their complaint alleged both negligence and strict liability claims for defective design, failure to warn, and negligent manufacturing. Unlike our case, however, which involves a rigorous review under the PMA process, Medtronic began marketing the pacemaker lead in
Lohr
after the FDA had found only that the device was “substantially equivalent” to devices already on the market under § 510(k). Indeed, the FDA itself “emphasized ... that [the § 510(k) notification process] should not be construed as an endorsement of the pacemaker lead’s safety.”
Lohr,
The Court’s reasoning largely focused on the requirements of the FDA’s regulation interpreting § 360k, cited and quoted earlier in this opinion. The Court observed that certain factors must be present, according to the regulations, before § 360k would preempt state requirements. First, there must be a state requirement specifically developed with respect to medical devices that is different from or in addition to federal requirements. Second, the state requirement must relate to the safety or effectiveness of the device, or “ ‘other matter included in a requirement applicable to the device.’ ”
Lohr,
Although the Court concluded that Lohr’s tort claims were not preempted, the majority split on the broader question of whether the duties enforced by common law actions could ever be “requirements” for the purpose of preemption. The four justice plurality written by Justice Stevens, distinguishing the MDA from the statute in
Cipollone v. Liggett Group, Inc.,
The meaning of
Lohr
as applied to our case becomes confusing at this point. Concurring with only parts of the majority
*579
writing, Justice Breyer found that the MDA could in fact preempt state tort suits. Relying on
Cipollone,
in which the “Court made clear that similar language ‘easily’ encompassed tort actions,” he reasoned that a state requirement that takes the form of a duty of care is essentially no different from a state statute or regulation.
Id.
at 504,
The four justices concurring in part and dissenting in part, relying on the § 360k preemption language and not the FDA’s regulations, concluded that “state common-law damages actions do impose ‘requirements’ and are therefore pre-empted where such requirements would differ from those imposed by the FDCA.”
Id.
at 509,
Because only parts of Justice Stevens’s opinion commanded a majority, extracting the final meaning of Lohr is no easy task. Assessing Lohr in the light of the three requirements for preemption described above, the Court first held that general common law duties do not impose requirements that are different from or in addition to the § 501(k) process. The Court offers no clear guidance on when the common law may satisfy the second factor, that is, that the state requirement relate to the safety or effectiveness of the device or establish a “substantive requirement” for a specific device. Although Justice Breyer’s concurrence very specifically disavows the view that common law duties cannot provide substantive requirements for the purpose of preemption, neither his concurrence nor the plurality opinion offers much help to us in developing the point. As to the third factor, the Court held that the FDA’s “substantially equivalent” determination under the § 501(k) process is not a federal regulation specific to a particular device, at least under the facts of Lohr. Because these holdings do not explicitly or implicitly decide the case before us, we must compare Lohr with Stamps, the circuit precedent that we are required to follow. ■
C
Our decision in
Stamps,
*580
We then addressed the question of whether state tort claims could be considered state “requirements” under § 360k. Relying on the Supreme Court’s preemption doctrine as laid out in
Cipollone,
Ill
When we turn to consider the impact of
Lohr
on the precedential effect of
Stamps,
we can immediately conclude that the Supreme Court did not explicitly overrule the case. Neither do we think that
Lohr
implicitly requires us to disregard
Stamps
as controlling precedent.
5
Although
Stamps
gave § 360k a somewhat broader preemptive scope than the Supreme Court’s opinion in
Lohr,
6
none of the components of the preemption test in
Lohr
contradict the holding in
Stamps
as applied here. As noted above, the Supreme Court held that for preemption under § 360k, there must be a state requirement — which does not exclude common law tort duties — with respect to a medical device that relates to the safety or efficiency of a device, or establishes a substantive requirement for the device, that is different from or in addition to a specific federal requirement.
Lohr,
A
First,
Stamps
found that common law tort suits can impose state requirements for the' purposes of preemption.
Stamps,
B
Second,
Stamps
found that common law duties could be preempted “to the extent that they relate[d] to safety, effectiveness, or other MDA requirements.”
Stamps,
Justice Breyer joined in the majority’s finding that “general state common-law requirements in this suit were not specifically developed ‘with respect to’ medical devices,” and that “these state requirements escape preemption ... because their generality leaves them outside the category of requirements that § 360k envisioned to be' ‘with respect to’ specific devices such as pacemakers.”
Lohr,
[I]t makes little sense to argue that Justice Breyer would write separately to make clear his position that duties arising under state common law can constitute state law “requirements” which can be preempted by the MDA, and then agree that because tort law consists of generally applicable principles, it is always preempted, even in the face of specific federal requirements.
Papike v. Tambrands Inc.,
Of course, we are plainly bound to follow the majority opinion in
Lohr;
yet, we cannot fully grasp the opinion’s interpretation of when state common law requirements
*582
are considered “specifically developed with respect to medical devices” without Justice Breyer’s concurrence. The majority opinion says that general common law obligations are not a threat to federal requirements.
Id.
at 501,
We think it is important to read the portion of the majority opinion addressing specific state requirements narrowly to avoid adopting as controlling law the broadly worded plurality opinion. Using Justice Breyer’s concurrence as a guide, we can conclude only that general duties of care can generate specific requirements that conflict with specific FDA requirements. We read Justice Breyer’s special concurrence to recognize that, although a manufacturer’s general duty of care to avoid foreseeable dangers may be too general to merit preemption when there is no specific federal requirement, the proof required to establish a particularly alleged common law claim can be specific enough that the claim becomes preempted as an “additional” or “different” requirement than the FDA requirement.
8
This reasoning is consistent with the majority opinion; while the general duty, standing on its own, is not a threat to federal requirements and is not developed specifically “with respect to” medical devices, the elements needed to prove a violation of that general duty may be very specifically tailored to the device, and the state court action may therefore threaten specific federal requirements. Because the federal § 510(k) requirements were not specific, it was unnecessary in
Lohr
to reach that conflict. For instance, as an example of a general common law duty, the majority opinion uses a “general duty to inform users and purchasers of potentially dangerous items of the risks involved in their use.”
Id.
at 501,
Thus, reading the language in the majority opinion through the lens of Justice Breyer’s concurrence, we cannot say that Lohr overruled the holding of Stamps that common law tort claims challenging the safety or effectiveness of a device create specific requirements under state law. After Lohr, however, we need to consider more than whether the common law duties relate to safety, effectiveness, or other MDA requirements; we need to focus on whether the specific requirements imposed by those common law duties threaten to interfere with specific federal requirements.
C
Third,
Stamps
interpreted state tort causes of action as requirements “different from, or in addition to” the PMA process, thereby meriting preemption.
Stamps,
Stamps,
however, specifically disagreed with the proposition that “the lack of direct conflict between the state and federal regulations compelled] a finding of no preemption.”
Id.
at 1424. On the other hand, this proposition seems to have been adopted by the Supreme Court;
Lohr
notes that “[njothing in § 360k denies Florida the right to provide a traditional damages remedy for violations of common-law duties when those duties parallel federal requirements.”
Lohr,
D
Fourth, Stamps held that the PMA process imposed specific federal requirements as to labeling, manufacturing, and design for the purposes of preemption. 9 Here, *584 too, there is no conflict with Lohr. Although Lohr considered the application of the identical FDA regulation governing labeling, the labeling requirements in Lohr under the § 510(k) process were general; as it did not go through the PMA process, the labeling in Lohr was not specifically reviewed by the FDA.
On its face, therefore,
Lohr
is limited to a finding that the § 501(k) process does not create specific federal requirements that conflict with state tort actions. Indeed, the plurality’s opinion itself seems to leave this suggestion when it notes at several points in the course of its writing the very significant differences between the FDA’s § 510(k) approval and a PMA approval,
See, e.g.,
Thus, for all these reasons, we are fully convinced that
Stamps
has not been overruled and remains viable authority in this circuit to the extent that we have described. Instead of overruling
Stamps, Lohr
should be read to implicitly affirm our holding in
Feldt v. Mentor Corp.,
In sum, we simply cannot read Lohr as establishing a new rule of law that contradicts our preexisting case law as it applies in this appeal. Thus, although the broad holding of Stamps that the PMA process preempts state tort causes of action to the extent that they relate to safety, effectiveness or other MDA requirements is narrowed by Lohr’s finding that preemption requires substantive requirements imposed by common law duties to threaten federal requirements, Stamps remains controlling precedent for the purpose of this appeal.
IV
We turn now to apply Stamps, as narrowed by Lohr, to the case before us. The plaintiffs allege that Medtronic breached state law duties by designing a pacemaker lead that contained certain materials, by labeling the lead with certain warnings, and by manufacturing the lead in a certain way. The design of the lead, the labeling on the lead, and the manner of manufacturing of the lead were all submit *585 ted to the FDA in great detail and approved by the FDA in the PMA process. Like the inadequate labeling, failure to warn, and defective design claims in Stamps, the plaintiffs’ claims that the district court found to be preempted relate to areas specifically covered in the PMA process, and seek to impose requirements that are different from and, indeed, conflict with the PMA process.
The district court specifically found those claims that paralleled the federal process — the claims that Medtronic did not adequately comply with the PMA process — were not preempted under § 360k. This finding comports with Lohr, that general duties of care that parallel federal requirements are not “different from, or in addition to” federal requirements, and are therefore not preempted.
In Stamps, our circuit spoke to the precise question presented in this appeal. And we have concluded here that the Supreme Court’s fractured ruling in Lohr does nothing to upset Stamps’s binding authority as respects this particular appeal. We therefore reaffirm that a medical device manufacturer’s compliance with the FDA’s PMA process will preempt state tort law claims brought with respect to that approved device and relating to safety, effectiveness or other MDA requirements when the substantive requirements imposed by those claims potentially conflict with PMA approval. Thus, the plaintiffs’ tort law claims relating to design, manufacturing process, and failure to warn are preempted by the MDA.
V
For the reasons stated above, the judgment of the district court is
AFFIRMED.
Notes
. The cases have been consolidated for the purposes of appeal only. The appellants, *575 however, brief their appeal as if the district court considered their cases on a consolidated basis. Therefore, we treat the procedural history in the same manner.
. Under the FDA’s PMA process, the manufacturer of the medical device must submit a detailed application to the FDA, including information on product specifications, manufacturing, intended use and proposed labeling. Qualified experts review each application and prepare a report and recommendation. The FDA then has six months to accept or reject the application.
See
21 U.S.C. § 360e;
Stamps v. Collagen Corp.,
. The section number refers to the original section of the MDA containing the provision.
. As the Supreme Court itself has observed, the PMA process and the § 510(k) process are clearly distinguishable.
See Lohr,
. In fact, after
Lohr,
both the Sixth and the Seventh Circuits determined that the PMA process constitutes specific federal requirements that preempt state tort suits.
Kemp v. Medtronic,
. For instance,
Stamps
notes that "section 3.60(k) ... ‘sweeps broadly’ and encompasses common law tort actions within its preemptive scope.”
Stamps,
. Justice Breyer even notes that “it is possible that the plurality also agrees” that
insofar as the MDA pre-empts a state requirement embodied in a state statute, rule, regulation, or other administrative action, it would also pre-empt a similar requirement that takes the form of a standard of care or behavior imposed by a state-law tort action.
Lohr,
. However, common law duties that incorporate the PMA process, such as the general duty to take due care to comply with the PMA process in labeling or manufacturing, will never contain specific requirements that are additional to or different from federal requirements. Therefore, claims based on those duties are not preempted.
See Lohr,
. During the PMA process, the FDA reviews the proposed labeling as well as the ingredients, components, methods, controls, and facilities used in the manufacture and processing of the device. 21 U.S.C. § 360e(c)(l)(B)-(C), (F). If any element of the manufacturing *584 does not comply with regulations, or labeling is found to be false or misleading, the application for approval is denied. Id. § 360e(d)(2)(A)-(D).
. See
also id.
at 480,
. Our decision in
Feldt,
