NESHAP Air Emissions: Do Medical Sites Comply?

Introduction

The blunt answer to "does EPA's radionuclide NESHAP apply to my medical facility?" is, for the great majority of facilities, no — and knowing why saves you from building a compliance program you do not need while missing the rules that actually bind you. EPA rescinded 40 CFR Part 61 Subpart I as applied to NRC-licensed and Agreement State licensed facilities in 1996, after finding that the NRC program already protects the public with an ample margin of safety. ^{1, 2, 3}

This is a recurring source of confusion. A new radiation safety officer reads about the Clean Air Act's National Emission Standards for Hazardous Air Pollutants (NESHAP) for radionuclides, sees a 10 mrem-per-year air-emission standard, and wonders whether the hospital owes EPA a compliance demonstration. The honest, current answer requires untangling a piece of 1990s regulatory history — and then pointing to the NRC rule that carries the real obligation today. ^{3, 4}

This article explains what the radionuclide NESHAP is, why Subpart I was rescinded for NRC licensees, which facilities remain covered, and — most importantly — what actually governs a medical facility's radioactive air emissions now: the NRC (or Agreement State) 10 mrem-per-year air-emission constraint and the 100 mrem-per-year public dose limit. DRPS helps facilities get this right through its radiation safety officer and radioactive material license support services across Florida, Maryland, Virginia, Washington DC, California, Nevada, Pennsylvania, New York, New Jersey, and Delaware.

Topic Explanation

What the radionuclide NESHAP is

Under Section 112 of the Clean Air Act, EPA sets National Emission Standards for Hazardous Air Pollutants. Radionuclides are one of the listed hazardous air pollutants, and 40 CFR Part 61 contains several radionuclide subparts, each aimed at a category of emitter. The two that frame this discussion are: ¹

Subpart H — radionuclide emissions from Department of Energy facilities.
Subpart I — originally, radionuclide emissions from NRC-licensed facilities and federal facilities not owned or operated by DOE.

The common thread across the radionuclide NESHAP subparts is a dose-based standard: emissions to ambient air must not cause any member of the public to receive an effective dose equivalent exceeding 10 mrem (0.1 mSv) per year. ^{1, 2}

The dual-regulation problem and the 1996 rescission

EPA promulgated the radionuclide NESHAP in 1989. The NRC and affected licensees immediately objected that NRC-licensed facilities would be regulated twice for the same emissions — once under the NRC's own public-protection rules and again under EPA's NESHAP. ³

The 1990 Clean Air Act Amendments gave EPA a way out. Section 112(d)(9) — sometimes called the Simpson amendment — allows EPA to decline to regulate radionuclide emissions from NRC-licensed facilities if the Administrator determines that the NRC's regulatory program provides an ample margin of safety to protect public health. ^{3, 4}

EPA made that determination. As part of the resolution, the NRC added an explicit air-emission constraint to its own rules — 10 CFR 20.1101(d), the 10 mrem-per-year limit on dose to the public from air emissions — and EPA agreed not to separately inspect NRC licensees. EPA then rescinded Subpart I for NRC and Agreement State licensees, with the final rescission effective at the end of 1996. ^{3, 4, 5}

The current title of Subpart I reflects the outcome: "National Emission Standards for Radionuclide Emissions From Federal Facilities Other Than Nuclear Regulatory Commission Licensees and Not Covered by Subpart H." The words "Other Than Nuclear Regulatory Commission Licensees" are the whole story. ²

Who is still covered

After the rescission, Subpart I applies to a narrow set of federal facilities — those that are neither NRC licensees nor DOE facilities (which fall under Subpart H). Most private hospitals, academic medical centers, and imaging and nuclear medicine practices are NRC or Agreement State licensees and therefore fall outside Subpart I. A facility that believes it might be an exception (for example, certain federal facilities) should confirm its status rather than assume. ²

Key Technical Principles

What actually binds a medical facility

For an NRC or Agreement State licensee, the operative air-emission requirement lives in the NRC rules, not in EPA's:

10 CFR 20.1101(d) — to implement ALARA, the licensee must constrain air emissions so that the individual member of the public likely to receive the highest dose does not exceed 10 mrem (0.1 mSv) per year from those emissions. This is the direct descendant of the NESHAP negotiation. ⁵
10 CFR 20.1301 — the total effective dose equivalent to an individual member of the public from the licensed operation must not exceed 100 mrem (1 mSv) per year from all pathways combined. ⁶
10 CFR 20.1302 — sets out how to demonstrate compliance with the public dose limit, including by calculation or by comparison to the effluent concentration values in 10 CFR 20 Appendix B. ⁷

The relationship between the two dose numbers is worth making explicit. The air-emission constraint is a fraction of the total public dose limit:

\frac{10 mrem/yr (air constraint)}{100 mrem/yr (public limit)} = 0.10

In other words, the air pathway alone is held to 10% of the all-pathway public dose limit — a deliberately conservative sub-limit that leaves headroom for other pathways and is the practical target a facility designs its effluent controls around. ^{5, 6}

Demonstrating compliance: the summation rule

The most common documentary demonstration under 10 CFR 20.1302 is to show that the annual average concentration of each radionuclide released to an unrestricted area stays within the effluent concentration (EC) limits of 10 CFR 20 Appendix B, Table 2. When more than one radionuclide is released — the norm in nuclear medicine — the summation (unity) rule applies: the sum of the ratios of each released concentration to its effluent limit must not exceed one. ⁷

i \sum \frac{C _{i}}{E C _{i}} \leq 1

Here $\overline{C}_{i}$ is the annual average released concentration of radionuclide $i$ at the point of public exposure and $E C_{i}$ is its Appendix B, Table 2 air effluent concentration. Meeting this test is the deemed-compliant pathway; alternatively, a facility can perform an explicit maximally-exposed-individual dose calculation using release quantities, dispersion modeling, breathing rate, and published dose coefficients. ⁷

How far below the limits medical emissions usually sit

For most medical facilities the calculated public dose from air emissions is far below the 10 mrem-per-year constraint. Volatile radioiodine (I-131) is the radionuclide of most concern, yet the exhaled activity after I-131 therapy is minute, and even in facilities that handle it, room ventilation and charcoal effluent controls reduce releases further. Published comparative work notes that routine airborne radionuclide emissions from far larger nuclear operations produce negligible public doses — on the order of less than 0.1 µSv per year — which underscores how much margin a well-controlled medical program typically retains against a 100 µSv (10 mrem) constraint. ⁸

Framework	Who it governs	Standard	Status for a typical medical facility
40 CFR 61 Subpart I	Federal facilities other than NRC licensees and not DOE	10 mrem/yr EDE from air	Does not apply (rescinded for NRC/Agreement State licensees, 1996)
40 CFR 61 Subpart H	Department of Energy facilities	10 mrem/yr EDE from air	Does not apply
10 CFR 20.1101(d)	NRC / Agreement State licensees	10 mrem/yr from air emissions (ALARA constraint)	Applies
10 CFR 20.1301	NRC / Agreement State licensees	100 mrem/yr TEDE to public, all pathways	Applies

Clinical Impact

Getting the compliance posture right

The practical consequence of understanding the rescission is that a medical facility should not build an EPA NESHAP reporting program it does not owe — no annual NESHAP report to EPA, no EPA compliance model runs — while it must maintain the NRC or Agreement State obligations that carry the real requirement. Confusing the two wastes effort in one direction and creates a genuine compliance gap in the other. For the broader public-dose framework, see public dose limits under Part 20 and airborne effluent and public dose.

Where air emissions actually matter in a medical program

The air pathway is most relevant where volatile or gaseous radioactive material is handled: I-131 therapy and diagnostic capsules, Xe-133 ventilation studies, and any radioiodine handling in the hot lab. These are the areas where a facility should focus effluent controls — fume hoods, charcoal traps, and appropriately exhausted ventilation — and where the compliance demonstration under 20.1302 has real content. See radioactive gas handling and effluent control for the engineering side, and I-131 hyperthyroidism therapy dosimetry for the clinical context.

Documentation is the deliverable

Because the dose margins are usually large, the risk for a medical facility is rarely an actual overexposure — it is a documentation gap at inspection. The facility should be able to show, on paper, that it identified the applicable rule (NRC/Agreement State, not NESHAP), set the 10 mrem/yr air constraint as an ALARA design goal, and demonstrated compliance with the public dose limit under 20.1302. That record is what an inspector expects to see.

Practical Optimization Tips

1. Confirm your jurisdiction first

Establish whether your facility is an NRC licensee or an Agreement State licensee, and confirm you are not one of the narrow federal exceptions still under Subpart I. This single determination sets the entire compliance posture.

2. Adopt the 10 mrem/yr air constraint as a written ALARA goal

Whether framed under 20.1101(d) or its Agreement State equivalent, put the air-emission constraint in your radiation protection program as an explicit ALARA design goal, not an implicit assumption.

3. Choose one compliance-demonstration method and document it

Decide whether you will demonstrate public dose compliance by calculation or by the Appendix B effluent-concentration summation rule, and keep the supporting numbers in your records. Update it when your radionuclide use changes materially.

4. Match effluent controls to the volatile radionuclides you actually use

Focus ventilation and charcoal controls where I-131 and other volatile or gaseous agents are handled. A facility that does no radioiodine work has a very different air-emission profile than a busy thyroid-therapy program.

5. Fold it into the annual program review

Revisit the air-emission compliance basis during the annual radiation protection program audit, especially after any change in radionuclide inventory or ventilation. See the annual radiation protection program audit.

Common pitfalls to avoid

Building a NESHAP program you do not owe. For NRC/Agreement State licensees, Subpart I was rescinded; do not report to EPA under it.
Assuming "no NESHAP" means "no rule." The 20.1101(d) and 20.1301 obligations are real and enforced.
Ignoring the summation rule. With multiple radionuclides, each ratio must be summed, not evaluated in isolation.
Skipping documentation because doses are low. Low dose does not excuse a missing compliance demonstration at inspection.
Forgetting the Agreement State difference. In an Agreement State, the state — not the NRC — administers and enforces the equivalent rules.

Regulatory Considerations

A defensible position on radioactive air emissions rests on correctly identifying which framework applies and documenting compliance with it.

40 CFR Part 61, Subpart I — the radionuclide NESHAP that once covered NRC licensees; rescinded for NRC and Agreement State licensees in 1996 and now limited to certain non-NRC, non-DOE federal facilities. ^{1, 2, 3}
Clean Air Act Section 112(d)(9) — the statutory authority that let EPA decline to regulate NRC licensees on finding the NRC program provides an ample margin of safety. ³
10 CFR 20.1101(d) — the NRC 10 mrem/yr air-emission constraint that carries the substantive requirement for licensees today. ⁵
10 CFR 20.1301 and 20.1302 — the 100 mrem/yr public dose limit and the methods to demonstrate compliance. ^{6, 7}

Agreement States administer equivalent rules. Of the states DRPS serves, Florida, Maryland, Virginia, California, Nevada, Pennsylvania, New York, and New Jersey are NRC Agreement States that enforce their own compatible public-dose and air-emission provisions, while Washington, DC and Delaware are regulated directly by the NRC for radioactive material. A facility must confirm which authority licenses it and which records that authority expects. For related obligations, see NRC occupational dose limits under Part 20 and building an ALARA program.

Frequently Asked Questions (FAQs)

Does EPA NESHAP Subpart I apply to my medical facility?

For the great majority of medical facilities, no. EPA rescinded 40 CFR Part 61 Subpart I as applied to NRC-licensed facilities and Agreement State licensees in 1996, after concluding that the NRC's regulatory program provides an ample margin of safety to protect public health, as allowed under Clean Air Act Section 112(d)(9). A privately operated hospital or imaging center licensed by the NRC or an Agreement State is therefore not subject to Subpart I. The rules that do apply come from the NRC or the Agreement State.

If NESHAP does not apply, what limits my facility's radioactive air emissions?

The operative federal requirement is NRC 10 CFR 20.1101(d), which requires that the individual member of the public likely to receive the highest dose not exceed 10 mrem (0.1 mSv) per year from air emissions of radioactive material, as part of the facility's ALARA program. On top of that, 10 CFR 20.1301 caps the total effective dose equivalent to a member of the public at 100 mrem (1 mSv) per year from all pathways, and 10 CFR 20.1302 sets out how to demonstrate compliance. Agreement States administer equivalent rules.

Why did EPA rescind Subpart I for NRC licensees?

When EPA first promulgated the radionuclide NESHAP in 1989, both the NRC and affected licensees objected to being regulated twice for the same emissions — once by the NRC and once by EPA. Clean Air Act Section 112(d)(9), added in the 1990 amendments, lets EPA decline to regulate NRC-licensed facilities if the Administrator finds the NRC program provides an ample margin of safety. EPA made that finding, the NRC added the 10 mrem/yr air constraint to 10 CFR 20.1101(d), and EPA rescinded Subpart I for NRC and Agreement State licensees, with the final action effective at the end of 1996.

Which facilities are still covered by Subpart I today?

The current Subpart I applies to federal facilities that are not licensed by the NRC and are not covered by Subpart H (which covers Department of Energy facilities). In other words, it fills a gap for certain federal facilities outside the NRC and DOE systems. Most private and academic medical facilities are NRC or Agreement State licensees and fall outside it.

Do I still need to monitor and control radioactive air effluents?

Yes. Being outside NESHAP does not remove the NRC or Agreement State obligations. Facilities must still keep public dose from air emissions below the 10 mrem/yr constraint and total public dose below 100 mrem/yr, demonstrate compliance under 10 CFR 20.1302 (typically by calculation or by showing released concentrations stay within the 10 CFR 20 Appendix B effluent limits), and maintain effluent controls such as charcoal traps and room ventilation where volatile radioiodine is handled.

How do I demonstrate compliance with the public dose limit for air emissions?

The common methods under 10 CFR 20.1302 are to perform a dose calculation for the maximally exposed member of the public using release data and dispersion modeling, or to show that the annual average concentration of radioactive material released to unrestricted areas does not exceed the effluent concentration values in 10 CFR 20 Appendix B, Table 2, applying the summation rule when more than one radionuclide is released. Either approach should be documented in the radiation protection program records.

Does being in an Agreement State change the NESHAP answer?

The NESHAP rescission applied to both NRC licensees and Agreement State licensees, so the Subpart I answer is the same. What changes is the administering authority: in an Agreement State, the state radiation-control program — not the NRC — licenses the facility, receives reports, and enforces the public dose limit and the air-emission constraint through its own regulations, which are compatible with the NRC rules.

Key Takeaways

Subpart I does not apply to NRC or Agreement State licensees. EPA rescinded it for them in 1996 under Clean Air Act Section 112(d)(9).
The real requirement is NRC 10 CFR 20.1101(d). The 10 mrem/yr air-emission constraint is the operative rule, backed by the 100 mrem/yr public dose limit of 20.1301.
The air constraint is 10% of the public dose limit. It is a deliberately conservative sub-limit that shapes effluent-control design.
Demonstrate compliance and document it. Use a dose calculation or the Appendix B summation rule under 20.1302, and keep the record.
Focus controls on volatile radionuclides. I-131 and Xe-133 handling is where the air pathway actually matters.
Know your administering authority. In an Agreement State, the state — not the NRC or EPA — enforces the equivalent rules.

Conclusion

The radionuclide NESHAP is a genuine regulatory framework, but for the medical facilities DRPS serves it is largely a historical footnote: EPA handed regulation of NRC-licensed and Agreement State licensed emitters back to the NRC and the states in the mid-1990s, on the finding that their programs already protect the public with ample margin. The requirement did not disappear — it moved. Today it lives in 10 CFR 20.1101(d)'s 10 mrem-per-year air constraint and 20.1301's 100 mrem-per-year public dose limit, enforced by the NRC or by an Agreement State.

For a radiation safety officer, the takeaway is clarity: do not spend effort on an EPA program you no longer owe, and do make sure the air-emission constraint is written into your ALARA program, demonstrated under 20.1302, and supported by effluent controls where volatile radionuclides are handled. Getting the framework right is the difference between a clean inspection and an avoidable finding.

How DRPS Can Help

Diagnostic Radiation Physics Services helps facilities identify exactly which radiation rules apply and document compliance with them. For air-emission questions, that can include confirming NRC versus Agreement State jurisdiction, writing the 10 mrem/yr air constraint into the radiation protection program, building the public-dose compliance demonstration under 10 CFR 20.1302, reviewing effluent controls for radioiodine and radioactive gas handling, and preparing the records an inspector expects — delivered through our radiation safety officer, radioactive material license support, and medical physicist consulting services.

DRPS supports facilities across our service locations, including Florida, Maryland, Virginia, Washington DC, California, Nevada, New York, Pennsylvania, New Jersey, and Delaware.

Compliance starts with citing the right rule — and for most medical facilities, that rule is the NRC's, not EPA's.

Related Resources

References

U.S. Environmental Protection Agency. 40 CFR Part 61, Subpart I: National Emission Standards for Radionuclide Emissions From Federal Facilities Other Than Nuclear Regulatory Commission Licensees and Not Covered by Subpart H. ecfr.gov
U.S. Environmental Protection Agency. Subpart I: National Emission Standards for Radionuclide Emissions From Federal Facilities Other Than NRC Licensees (resources page). epa.gov
U.S. Environmental Protection Agency. Rescission of Subpart I for NRC-licensed and non-DOE federal facilities; Federal Register final action. December 30, 1996. govinfo.gov
U.S. Congress. Clean Air Act, Section 112(d)(9) (radionuclide emissions from NRC-licensed facilities). 42 U.S.C. 7412(d)(9). epa.gov
U.S. Nuclear Regulatory Commission. 10 CFR 20.1101: Radiation protection programs (paragraph (d), constraint on air emissions). nrc.gov
U.S. Nuclear Regulatory Commission. 10 CFR 20.1301: Dose limits for individual members of the public. nrc.gov
U.S. Nuclear Regulatory Commission. 10 CFR 20.1302: Compliance with dose limits for individual members of the public; 10 CFR 20 Appendix B. nrc.gov
Schomäcker K, Sudbrock F, Fischer T, Dietlein F, Dietlein M, Krapf P, Drzezga A. Airborne radioiodine: a comparative view of chemical forms in medicine, nuclear industry, and fallout scenarios. International Journal of Molecular Sciences. 2026;27(2):590. doi:10.3390/ijms27020590. doi.org