NRC, Agreement States & FDA: Who Regulates What

Medical radiation in the United States is governed by two parallel regulatory systems, and the single most common compliance mistake is confusing them. Reactor- and accelerator-produced radioactive material is regulated by the U.S. Nuclear Regulatory Commission (NRC) or by an Agreement State under rules modeled on 10 CFR Parts 20 and 35. X-ray-producing machines are regulated by the U.S. Food and Drug Administration (FDA) for the equipment and by the state radiation-control program for its use. ^{1, 2, 3, 5}

A facility that runs both a nuclear medicine clinic and a CT scanner answers to both systems at once, often through different agencies, different application forms, and different inspectors. Understanding which authority owns which hazard is the foundation of a defensible radiation safety program, and it is usually the first question we help a new imaging or therapy facility sort out.

Introduction

When a facility asks "who do we call to get licensed?", the honest answer is "it depends on what kind of radiation you are using." That is not evasion — it is the structure of U.S. radiation regulation. The legal dividing line is not how dangerous a source is or how much dose it can deliver; it is what kind of radiation the source produces and how that material came to exist. ^{1, 2}

On one side sits byproduct material — radioactive material produced in a nuclear reactor or, since 2005, in a particle accelerator — which is federal property of a sort: it is regulated under the Atomic Energy Act by the NRC, or by a state the NRC has formally empowered to act in its place. On the other side sit radiation-producing machines — x-ray tubes in radiography, fluoroscopy, CT, dental, and mammography units — which the NRC has no statutory authority over at all. These are handled by the FDA at the point of manufacture and by the states at the point of use. ^{1, 3, 5}

This guide walks through both systems, the Agreement State concept that ties them together, the worked dose limits that every program shares, the clinical impact of getting jurisdiction right, and the practical steps DRPS uses to map a facility's sources to the correct regulator. DRPS provides this analysis as part of radiation safety officer and radioactive material license support work across Florida, Maryland, Virginia, Washington DC, California, and Nevada.

Topic Explanation

The two regulatory domains

The first domain is byproduct material. Under the Atomic Energy Act of 1954, as amended, the NRC regulates source material, special nuclear material, and byproduct material. For medical physics, byproduct material is the category that matters: it includes the reactor-produced radionuclides used every day in nuclear medicine and radiopharmaceutical therapy — Tc-99m, I-131, Lu-177, Y-90 — and, following the Energy Policy Act of 2005, accelerator-produced radionuclides such as the PET isotopes F-18, Ga-68, and C-11, plus discrete sources of radium-226. ¹ The controlling rules are 10 CFR Part 20 (Standards for Protection Against Radiation) and 10 CFR Part 35 (Medical Use of Byproduct Material). ^{2, 3}

The second domain is the x-ray-producing machine. An x-ray tube only emits radiation when it is energized; when it is off, it is an inert piece of equipment, not a radioactive source. Because no radioactive material is involved, x-ray machines fall entirely outside the Atomic Energy Act and therefore outside NRC authority. Instead, the FDA regulates the manufacturer of the equipment under the Electronic Product Radiation Control provisions of the Federal Food, Drug, and Cosmetic Act, with performance standards codified in 21 CFR Part 1020, while each state regulates the user — registration of the tube, operator credentialing, shielding plan review, and periodic inspection — under its own radiation-control regulations. ^{5, 8}

What "byproduct material" actually covers

The scope of byproduct material is broader than many facilities assume, and the 2005 expansion is the detail people miss most often. Before 2005, a cyclotron-produced PET isotope such as F-18 was technically "accelerator-produced material" and was regulated by the states, not the NRC. The Energy Policy Act of 2005 amended the definition of byproduct material to include accelerator-produced radioactive material and certain discrete sources of naturally occurring radioactive material. ¹ As a result, a modern PET/CT program's F-18 FDG is byproduct material under NRC or Agreement State authority, while the CT half of that same scanner is an x-ray machine under FDA and state authority. One room, one patient, two regulators.

For background on how these isotopes are produced and used, see Understanding Common Isotopes in PET & Radiopharmaceutical Therapy and Cyclotron Production of F-18.

The FDA's two distinct roles

It is worth separating the FDA's two very different jobs, because facilities routinely conflate them. First, the FDA regulates x-ray equipment as an electronic product that emits radiation, setting manufacturing performance standards under 21 CFR Part 1020 (for example, 1020.30-33 for diagnostic x-ray systems, CT, and fluoroscopy). ⁵ Second, and completely separately, the FDA approves radiopharmaceuticals as drugs under the Federal Food, Drug, and Cosmetic Act. A Lu-177 therapy agent is an FDA-approved drug and NRC- or Agreement-State-regulated byproduct material at the same time. The FDA says the drug is safe and effective; the NRC or Agreement State says you may possess and administer the radioactivity safely. Neither agency's approval substitutes for the other's.

Key Technical Principles

Mapping a source to its regulator

The table below summarizes how the common medical radiation sources map to their regulators. The pattern to internalize: material means NRC or Agreement State; machine means FDA plus state.

The dividing line is statutory, not risk-based. A high-output CT scanner can deliver far more population dose than a low-activity sealed source, yet the CT scanner is a state-regulated x-ray machine and the sealed source is NRC- or Agreement-State-regulated byproduct material. Jurisdiction follows the nature of the source, not the magnitude of the hazard. ^{1, 5}

The dose limits are shared

One thing that does not change across the jurisdictional boundary is the underlying radiation-protection framework. Both the NRC's 10 CFR Part 20 and the states' x-ray regulations are built on the same dose-limit system, expressed in the same quantities. Because U.S. regulations are still written in conventional units (rem) while the scientific literature uses SI units (sievert), it is worth being fluent in the conversion: ²

The occupational total effective dose equivalent (TEDE) limit in 10 CFR 20.1201 is 5 rem per year, and the public dose limit in 10 CFR 20.1301 is 0.1 rem per year: ²

10 CFR 20.1301 also caps the dose in an unrestricted area at 0.002 rem (0.02 mSv) in any one hour. ² Most state x-ray regulations adopt the identical occupational and public limits, because the states' rules are harmonized to the federal framework through the model regulations discussed below. The shielding calculation that protects a receptionist next to a CT room and the shielding calculation that protects the same receptionist next to a PET uptake room are evaluated against the same 1 mSv/yr public design goal, even though the two rooms answer to different regulators. See Time, Distance, and Shielding for how those limits drive barrier design.

How the states stay harmonized

If every state wrote its own radiation rules from scratch, a facility operating in multiple states would face chaos. Two mechanisms prevent that. For byproduct material, the NRC requires each Agreement State's program to remain "compatible" with the NRC's rules as a condition of the agreement, so 10 CFR Part 35 requirements reappear, nearly verbatim, in Agreement State regulations. ^{1, 4} For x-ray machines, the Conference of Radiation Control Program Directors (CRCPD) publishes the Suggested State Regulations for Control of Radiation (SSRCR), a model code most states adopt with local modifications. ⁸ The result is a patchwork that is far more uniform than its structure suggests — but "nearly uniform" is not "identical," and the local variations are exactly where an unprepared facility gets tripped up.

Clinical Impact

Getting jurisdiction right is not an academic exercise; it determines the entire compliance workflow of an imaging or therapy facility.

Consider a new outpatient center opening a PET/CT suite and a nuclear medicine clinic in an Agreement State such as Florida, Maryland, or Virginia. The F-18, Tc-99m, and any therapy isotopes require a radioactive material license from the state radiation-control program, written to rules modeled on 10 CFR Part 35, naming an authorized user and a radiation safety officer. ^{3, 4} The CT scanners and any fluoroscopy units require machine registration with the same state's x-ray program under a different set of regulations, often administered by a different section of the same agency, with different fees, different renewal cycles, and different inspectors. ^{5, 8} A facility that applies for one and forgets the other can be fully "licensed" for its radioactive material and still be operating unregistered x-ray equipment — a finding that surfaces quickly during an inspection.

Now move the same facility to Washington, DC or Delaware. Because both are non-Agreement jurisdictions, the radioactive material license now comes from the NRC directly, not a local program, and reports of medical events, lost sources, or overexposures go to an NRC regional office rather than a state bureau. ^{6, 7} The x-ray machines, however, are still state/district-regulated, because the FDA-plus-state structure applies everywhere regardless of Agreement status. The jurisdiction map literally changes when you cross a state line, and a multi-site operator has to maintain a current map for every location. For a worked example of one state's requirements, see Florida Radiation Safety Requirements for Imaging Centers.

The incident-reporting consequence is the one with the sharpest teeth. A medical event under 10 CFR 35.3045 — a dose far outside the prescribed range — must be reported to the correct regulator within strict deadlines. ³ Reporting it to the wrong agency, or not knowing which agency to call, does not stop the clock. The reporting obligation is defined by jurisdiction, and jurisdiction is defined by the source.

Practical Tips

A facility can avoid almost all jurisdictional confusion by doing a few things deliberately at startup and then revisiting them whenever the source inventory changes.

• Inventory every source by type, not by location. List each radioactive material and each x-ray machine separately. For each line, write down the regulator, the governing rule, the license or registration number, and the renewal date. This single table is the backbone of the program.
• Confirm your Agreement status before you apply. Check the NRC's current list of Agreement States for the state in question. If the facility is in a non-Agreement jurisdiction (including DC and Delaware), the radioactive material application goes to the NRC; otherwise it goes to the state program. ^{4, 6}
• Do not assume one license covers everything. A radioactive material license never covers x-ray machines, and an x-ray registration never covers radioactive material. Multi-modality facilities almost always need both credentials.
• Treat PET isotopes as byproduct material. Since 2005, cyclotron-produced PET isotopes are NRC/Agreement-State byproduct material, not state-only accelerator material. ¹ Build the F-18 program under 10 CFR Part 35, not under the x-ray rules.
• Separate the drug question from the radiation-safety question. FDA drug approval and NRC/Agreement-State possession authority are independent. Confirm both before administering a new radiopharmaceutical.
• Keep the regulator contacts current. Know which regional NRC office or which state bureau receives your reports, and verify the contact annually. The time to learn the reporting path is not during a medical-event deadline.

For facilities building or revising this structure, DRPS integrates the jurisdiction map into radiation safety officer program support and medical physics consulting.

Regulatory Considerations

The legal architecture rests on the Atomic Energy Act of 1954, as amended. The Act gives the NRC authority over byproduct, source, and special nuclear material, and Section 274 authorizes the NRC to enter into agreements with states — the "Agreement States" — to assume regulatory authority over most of that material within their borders. ¹ As of 2024, 39 states have signed such agreements. The NRC retains authority in the remaining non-Agreement states, the District of Columbia, and most U.S. territories. ⁴ Delaware and the District of Columbia are the two non-Agreement jurisdictions most relevant to DRPS's East Coast service area, and facilities there deal with the NRC directly. ^{6, 7}

The core medical rules are:

• 10 CFR Part 20 — Standards for Protection Against Radiation. Sets occupational and public dose limits, ALARA expectations, survey and monitoring requirements, posting and labeling, and waste controls. Adopted, in compatible form, by every Agreement State. ²
• 10 CFR Part 35 — Medical Use of Byproduct Material. Governs authorized users, the radiation safety officer, written directives, patient release, and radionuclide-specific requirements. ³ The program-specific licensing guidance is NUREG-1556, Volume 9. ⁹
• 21 CFR Part 1020 — FDA performance standards for ionizing-radiation-emitting products, including diagnostic x-ray systems, CT, and fluoroscopy. ⁵
• 21 CFR Part 900 — the Mammography Quality Standards Act regulations, under which the FDA requires facility accreditation, qualified personnel, and an annual medical physicist survey. ¹⁰ This is the one place the FDA directly regulates the use of an x-ray machine, not just its manufacture.

Agreement States administer their own equivalent programs. Of the states DRPS serves, Florida, Maryland, Virginia, California, Nevada, Pennsylvania, New York, and New Jersey are NRC Agreement States that license and inspect radioactive material under their own radiation-control rules, while Washington, DC and Delaware are regulated directly by the NRC. ^{4, 6, 7} Every facility must confirm which authority issues its license or registration and which incident-reporting path applies before relying on any assumption. For the mechanics of license applications and inspections, see NRC Materials License: A Practical Guide and Preparing for an NRC or Agreement State Inspection.

Frequently Asked Questions (FAQs)

Who regulates radioactive material used in nuclear medicine?

Reactor- and accelerator-produced radioactive material (byproduct material) such as Tc-99m, I-131, F-18, and Lu-177 is regulated by the U.S. Nuclear Regulatory Commission in non-Agreement States and by the state radiation-control program in the 39 Agreement States. Both use rules modeled on 10 CFR Parts 20 and 35.

Who regulates x-ray machines like CT, fluoroscopy, and radiography units?

X-ray machines are not byproduct material, so the NRC has no authority over them. The FDA regulates the manufacturer of the equipment under 21 CFR Part 1020, and the state radiation-control program regulates the facility that owns and operates the machine, including registration, shielding, and inspections.

What is an Agreement State?

An Agreement State is a state that has signed a formal agreement under Section 274b of the Atomic Energy Act, allowing it to assume NRC authority to license and inspect most radioactive material within its borders. As of 2024 there are 39 Agreement States; the NRC retains authority in the remaining non-Agreement States, the District of Columbia, and most territories.

Are Washington DC and Delaware Agreement States?

No. Both the District of Columbia and Delaware are non-Agreement jurisdictions, so radioactive material there is licensed and inspected directly by the NRC rather than by a state program. Facilities in those jurisdictions submit license applications and reports to the NRC.

Does the FDA regulate radioactive drugs as well as x-ray machines?

Yes, in a different role. The FDA approves radiopharmaceuticals as drugs under the Federal Food, Drug, and Cosmetic Act, while the NRC or Agreement State regulates the radiation safety of using those same drugs. A nuclear medicine dose therefore has both an FDA drug-approval dimension and an NRC/Agreement-State radiation-safety dimension.

Who regulates mammography equipment and facilities?

Mammography is dually controlled. The FDA administers the Mammography Quality Standards Act under 21 CFR Part 900, which governs facility accreditation, personnel, and annual physics surveys, while 21 CFR Part 1020.30-31 sets the equipment performance standard and the state program typically still registers the unit.

Why does it matter which regulator owns a given hazard?

The regulator determines which rules apply, who issues your license or registration, who inspects you, and where you report incidents. Sending a radioactive-material question to a state x-ray program, or applying federal x-ray equipment rules to a sealed source, wastes time and can leave real compliance gaps that surface during an inspection.

Key Takeaways

• Two parallel systems. Radioactive material is regulated by the NRC or an Agreement State; x-ray machines are regulated by the FDA (equipment) and the state (use). The dividing line is the nature of the source, not its hazard magnitude.
• Byproduct material includes PET isotopes. Since the Energy Policy Act of 2005, accelerator-produced PET isotopes are NRC/Agreement-State byproduct material, so a PET/CT suite answers to two regulators at once.
• 39 Agreement States, as of 2024. In those states the state program acts in the NRC's place for radioactive material; in non-Agreement jurisdictions — including DC and Delaware — the NRC acts directly.
• The dose limits are shared. Both systems use the same 10 CFR Part 20 framework: 50 mSv/yr occupational, 1 mSv/yr public. The regulator differs; the protection goal does not.
• You usually need both credentials. A multi-modality facility needs a radioactive material license and an x-ray machine registration — two applications, often two sections of the same agency.
• Jurisdiction defines the reporting path. Medical events and incidents must go to the correct regulator within strict deadlines; knowing the path in advance is part of the program.

Conclusion

The two-system structure of U.S. radiation regulation looks confusing because it is organized around the physics and legal origin of the source rather than around the facility that uses it. Once the operating principle is clear — material means NRC or Agreement State; machine means FDA plus state — the rest follows. A facility that maps each of its sources to the correct regulator, confirms its Agreement status, maintains both the radioactive material license and the x-ray registration, and knows its reporting path has eliminated the most common and most avoidable category of radiation-safety compliance failure.

The radiation safety officer and medical physicist should treat the jurisdiction map as a living document, revisited whenever the facility adds a modality, a new isotope, or a new location. The map is cheap to maintain and expensive to ignore.

How DRPS Can Help

Diagnostic Radiation Physics Services helps imaging and nuclear medicine facilities build radiation safety programs that match the correct regulatory framework from day one. This includes mapping each source to its regulator, radioactive material license support for NRC and Agreement State applications, x-ray machine registration guidance, radiation safety officer program development, and medical physics consulting that coordinates the material and machine sides of a multi-modality facility.

DRPS supports facilities across our service locations, including Florida, Maryland, Virginia, Washington DC, California, Nevada, New York, Pennsylvania, New Jersey, and Delaware — a service area that spans both Agreement States and NRC-direct jurisdictions, so we map each client to the authority that actually governs it.

Related Resources

• Florida Radiation Safety Requirements for Imaging Centers
• NRC Materials License: A Practical Guide
• NRC Agreement State Reciprocity and Form 241
• X-ray Machine Registration and Inspection
• NRC Occupational Dose Limits (10 CFR Part 20)
• Preparing for an NRC or Agreement State Inspection
• Radioactive Material License Support
• Radiation Safety Officer consulting

References

1. U.S. Nuclear Regulatory Commission. Atomic Energy Act of 1954, as amended (including Section 274 on Agreement States and the Energy Policy Act of 2005 byproduct-material amendments). nrc.gov
2. U.S. Nuclear Regulatory Commission. 10 CFR Part 20: Standards for Protection Against Radiation. ecfr.gov
3. U.S. Nuclear Regulatory Commission. 10 CFR Part 35: Medical Use of Byproduct Material. ecfr.gov
4. U.S. Nuclear Regulatory Commission. Agreement State Program (fact sheet and alphabetical list of Agreement States). nrc.gov
5. U.S. Food and Drug Administration. 21 CFR Part 1020: Performance Standards for Ionizing Radiation Emitting Products (including 1020.30-33 for diagnostic x-ray, CT, and fluoroscopy). ecfr.gov
6. U.S. Nuclear Regulatory Commission. Agreement States (hub covering non-Agreement jurisdictions, including the District of Columbia). nrc.gov
7. U.S. Nuclear Regulatory Commission. Delaware: Non-Agreement State Information. nrc.gov
8. Conference of Radiation Control Program Directors. Suggested State Regulations for Control of Radiation (SSRCR). crcpd.org
9. U.S. Nuclear Regulatory Commission. NUREG-1556, Volume 9, Revision 3: Program-Specific Guidance About Medical Use Licenses. nrc.gov
10. U.S. Food and Drug Administration. 21 CFR Part 900: Mammography (Mammography Quality Standards Act regulations). ecfr.gov