There are two types of federal air regulations, the National Emission Standards for Hazardous Air Pollutants (NESHAPs) and New Source Performance Standards (NSPSs). Either or both regulations may apply.
- NESHAPs can apply regardless of a facility needing an air permit.
- NSPSs can impact whether a facility needs an air permit.
National Emission Standards for Hazardous Air Pollutants (NESHAP)
The Clean Air Act requires the U.S. EPA to regulate emissions of air pollutants that are hazardous to human health or and the environment. These pollutants are called hazardous air pollutants (HAPs). HAPs are regulated by NESHAPs.
There are two types of facilities covered by NESHAPs:
- Major sources have the potential to emit more than 10 tons per year of a single HAP or 25 tons per year of any combination of HAPs.
- Area sources are not major sources and have the potential to emit less than 10 tons per year of a single HAP or 25 tons per year of any combination of HAPs. Many small businesses are area sources.
NESHAPs are federal air regulations, so whether you have an air permit or not, you will still need to meet the requirements of any applicable NESHAPs. Due to the number and variety of NESHAPs, it is likely that at least one applies to you. Review the list of NESHAPs.
New Source Performance Standards
NSPSs are like NESHAPs, meaning they are a federal air regulation. However, if an NSPS applies to you, an air permit may be required regardless of whether your potential to emit exceeds air permit thresholds. Minn. R. 7007.0300, subp.1(B) outlines the NSPSs that do not require a permit solely because one or more of the listed NSPSs applies to your facility. Boilers, stationary engines/generators, grain elevators, hot-mix asphalt plants, and aggregate processing are examples of common activities with NSPSs. Review the list of NSPSs.
Contact the Small Business Environmental Assistance Program helpline: 1-800-657-3938 or 651-282-6143 or email us at smallbizhelp.pca@state.mn.us for help identifying if a NESHAP or NSPS applies.
FAQs
Q: What standards do I follow if a NESHAP applies to my facility?
A: The EPA uses standards called Maximum Achievable Control Technologies (MACTs) to control and reduce HAP emissions from specific source categories. MACTs cover both major and area sources. There are some area source categories that use Generally Available Control Technologies (GACTs) instead of MACTs.
Q: I am subject to a major source NESHAP; will I always be subject to the major source NESHAP even if my HAP emissions are reduced?
A: In 1995 the EPA issued a “once in always in” policy. However, this policy was withdrawn in January 2018. Under the 1995 policy, once a source was subject to a major source NESHAP, it would always be subject to the standard, regardless of the source's emissions. Now that the policy is withdrawn, qualifying major sources can be reclassified as area sources. For more information: Reclassification of Major Sources as Area Sources Under Section 112 of the Clean Air Act.
Q: Are there volatile organic compound (VOCs) products that are exempt from federal regulation?
A: Yes, there are federally exempt VOCs. VOCs are any organic compounds that participate in smog-forming reactions, except for those designated by the U.S. EPA as having negligible photochemical reactivity. A list of exempted VOCs are available in Minn. R. 7005.0100, subp. 45 and the U.S. EPA’s complete list of VOC exemption rules.
Q: What is New Source Review (NSR)?
A: NSR is a pre-construction review program that is federally required for new major sources and major modifications at existing sources. For more information:
Q: What is Prevention of Significant Deterioration (PSD)?
A: PSD is how NSR is implemented in areas of NAAQs attainment. Most of Minnesota is in NAAQs attainment, except for lead in Dakota County. See our plan to control criteria air pollutants. PSD regulations apply to new major source and major source modifications at existing sources. For more information: