On this page:

• Rule Summary
• Rule History
• Additional Resources
• Compliance

Rule Summary

Subpart I protects the public and the environment from radionuclideradionuclideRadioactive forms of elements are called radionuclides. Radium-226, Cesium-137, and Strontium-90 are examples of radionuclides. emissions emitted by federal facilities that are not regulated elsewhere. Subpart I limits radionuclide emissions to the ambient airambient airThe air that surrounds us based on two criteria:

1. Emissions of radionuclides, including iodine, to the ambient air from a facility regulated under this subpart shall not exceed those amounts that would cause any member of the public to receive in any year an effective doseeffective doseThe amount of radiation absorbed by an object or person, adjusted to account for the type of radiation received and the effect on particular organs. The unit used for effective dose is rem (U.S. unit) or sievert (Sv, the international unit). equivalent (EDE) of  10 milliremmilliremThe millirem is the U.S. unit used to measure effective dose. One millirem equals 0.001 rem. The international unit is milliSievert (mSv). (0.1 millisievert).
2. Emissions of iodine to the ambient air from a facility regulated under this subpart shall not exceed those amounts that would cause any member of the public to receive in any year an EDE of 3 millirem (0.03 millisievert).

Federal facilities to which Subpart I does NOT apply include the following:

• DOE facilities (see Subpart H).
• Nuclear Regulatory Commission licensees (subject to NRC's regulatory program).
• Disposal activities that are subject to 40 CFR Part 191 Subpart B.
• Low-energy accelerators.
• Uranium mill tailingstailingsThe remaining portion of a metal-bearing ore after some or all of a metal, such as uranium, has been extracted. piles disposed of under 40 CFR Part 192.

Rule History

View the December 30, 1996 Federal Register notice regarding the rescission of 40 CFR Part 61, Subpart I (PDF)(10 pp, 156.47 K, About PDF).

Additional Resources

For supporting documents see, Subpart I: Resources.

Compliance

Owners or operators of these facilities must use the COMPLY computer model to calculate effective dose equivalent (EDE) or obtain approval from EPA to use other models. They are required to submit annual reports to EPA on emissions and obtain EPA's approval for some types of construction. 

All facilities subject to any NESHAP must meet 40 CFR Part 61, Subpart A: General Provisions.