Official State of Iowa Website Here is how you know

Air Toxics – NESHAP

The U.S. Environmental Protection Agency (EPA) and the Iowa DNR are required by law to reduce exposure to hazardous air pollutants (HAPs). EPA has issued over 120 National Emission Standards for Hazardous Air Pollutants (NESHAP). Approximately 50 of those NESHAP affect facilities in Iowa. DNR has developed implementation tools for the NESHAP in each section listed below.

Some NESHAP apply to both major and area sources of HAP, and some apply just to one or the other. Major sources are those with facility-wide potential or actual emissions of 10 tons per year or more of any single HAP or 25 tons per year or more of a combination of HAP. Area sources are those with potential and actual emissions below the major source thresholds.

Small Unit Exemption (SUE) Eligibility

A facility owner or operator is not eligible to use the small unit exemption (SUE) (567 IAC subrule 22.1(2)”w”) if an emission unit emits a hazardous air pollutants and is “required to be reviewed for compliance” with a National Emission Standard for Hazardous Air Pollutants (NESHAP). This DNR guidance document helps explain this requirement, and includes several examples of equipment that can still use the SUE, and some equipment that may no longer qualify for the SUE because of NESHAP requirements.

Small Business Assistance

Small businesses can obtain help with the area source NESHAPS through the Iowa Air Emissions Assistance Program. More information regarding this program, including the eligibility requirements, can be found on the Small Business Assistance website.

Other NESHAP Regulations and Implementation Tools
  • EPA's NESHAP Page
  • EPA’s Area Source Page (look for the subpart or the rule name in the table)
  • Nebraska DEQ site (Click on “Focus on Air on the left-side menu, scroll down until you see the link for “Air Toxics Program,” then click on link for “Jump to Air Toxics Notebook.” You can then click on the links to search by federal subpart or by industry category. There is not a direct link to this page. Note that any information regarding Nebraska facilities or Nebraska’s state rules are not applicable to Iowa DNR or facilities in Iowa).

+ Reciprocating Internal Combustion Engines (RICE) (major and area sources)

40 CFR Part 60, Subparts IIII and JJJJ, 40 CFR Part 63, Subpart

Air Toxics Standards for Stationary Engines

(40 CFR Part 63 Subpart ZZZZ, also known as RICE NESHAP*)

The RICE NESHAP was first promulgated in 2004, and has been amended several times since then. This NESHAP places requirements on owners and operators of a wide variety of stationary engines. DNR's adoption of the 2010 and 2013 RICE NESHAP amendments became effective on October 23, 2013. This means that DNR, rather than EPA, is now the primary authority for RICE implementation in Iowa, allowing the DNR to provide compliance assistance and outreach to facilities. RICE NESHAP responsibilities have been transferred from EPA to the DNR. * RICE NESHAP is the commonly-used acronym for the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Stationary Reciprocating Internal Combustion Engines (RICE) [40 Code of Federal Regulations (CFR) Part 63, Subpart ZZZZ]

Compliance Assistance Tools

DNR has created several compliance assistance tools for facilities subject to the RICE NESHAP.

To obtain information on whether a specific engine may be subject to the RICE NESHAP or whether it is in compliance with RICE NESHAP requirements, please contact Sarah Mousel at the DNR ( or call 515-725-8403).

EPA has developed the following RICE NESHAP implementation tools and guidance:

Permit Requirements for Stationary Engines

Construction Permit Amnesty for Engines

On October 23, 2013, the Iowa DNR, along with the Polk County and Linn County Air Quality Divisions, initiated an amnesty program for engines. The intent of the amnesty was to provide Iowa businesses an opportunity to "catch up on" air quality permitting requirements they had missed, without the risk of potential enforcement actions and penalties.

The amnesty period ended on April 23, 2014. DNR is pleased to report that 110 Iowa businesses, operating 127 engines, took advantage of the amnesty and submitted the past due permit applications, registrations, or permit exemption information.

Results of DNR Air Quality Bureau's 6-month amnesty period for as-built engines (includes Linn County and Polk County):

Requirement Number of facilities Number of Engines
Obtain Construction Permit 44 53
Submit Small Engine Registration 60 64
Submit Exemption "g" Notification 6 10
Totals 110 127

Registration Requirement for New Engines Smaller Than 400 Horsepower

Engine Registration Forms

Engine Registration FAQ


Notification Requirement for Installation of Control Equipment on Existing Engines

Control equipment may be installed on an existing stationary engine without modifying the engine's construction permit. This permitting exemption is allowed under 567 IAC 22.1(2) "g". Facilities choosing this option are required to submit a notification to DNR 30 days prior to installing the control equipment.

If the exhaust stack for the engine will be modified significantly, a construction permit may be necessary. If you have any questions about whether your engine qualifies for this permitting exemption, please call the Construction Permit Help Line (1-877-AIR-IOWA).


+ Boilers and Process Heaters (major and area sources)

40 CFR Part 63, Subpart DDDDD and Subpart JJJJJJ

Major Source Boilers and Process Heaters (5D)

General Information

Note: Facilities that already submitted an initial notification for the Major Source Boiler MACT promulgated on March 21, 2011, are not required to submit another initial notification at this time. Facilities that have not submitted an initial notification since the “old” Boiler MACT (promulgated in 2004) will need to submit a new notification.

Area Source Boilers (6J)

The Area Source Boiler NESHAP does not apply to process heaters, and it does not apply to “gas-fired boilers,” as defined in 6J: Gas-fired boiler includes any boiler that burns gaseous fuels not combined with any solid fuels and burns liquid fuel only during periods of gas curtailment, gas supply interruption, startups, or periodic testing on liquid fuel. Periodic testing of liquid fuel shall not exceed a combined total of 48 hours during any calendar year.

General Information

+ Metal Fabrication and Finishing (area sources)

40 CFR Part 63, Subpart XXXXXX

To help facilities understand new requirements to reduce air emissions from Metal Fabrication and Finishing operations, the Iowa DNR Air Quality Bureau and the Iowa Air Emissions Assistance Program (IAEAP) at the University of Northern Iowa have developed important compliance assistance tools. These tools will help you determine if you are subject to the new rule (6X NESHAP), and how to comply with the requirements. Existing facilities that are subject to the 6X NESHAP will need to comply with these new standards by July 25, 2011. To access the short and informative 6X NESHAP tutorials and other information, go to:

If you determine you are subject to the 6X NESHAP, you need to submit an “Initial Notification” by no later than July 25, 2011, and a “Notification of Compliance Status” by November 22, 2011. Please use these forms to complete the required notifications:

More 6X NESHAP tools:

For questions about the applicability of the 6X NESHAP to your facility, please call the Iowa DNR’s toll free air quality help line at 1-877-AIR-IOWA (1-877-247-4692). Small businesses (those with 100 or fewer Iowa employees) can also obtain free, confidential regulatory assistance from the IAEAP. You may also contact IAEAP by phone toll free at 1-800-422-3109.

+ Perc Dry Cleaning Facilities (major and area sources)

40 CFR Part 63, Subpart M

Dry cleaning facilities that use perchloroethylene (also known as perc or PCE) are subject to the National Emission Standards for Hazardous Air Pollutants (NESHAP). This rule includes requirements for control equipment, leak inspections and repair, and recordkeeping and reporting.

General Information:


Questions about Dry Cleaner NESHAP requirements may be directed to Sarah Mousel at DNR (email or call 515-725-8403). Small businesses (those with 100 or fewer Iowa employees) can also obtain free, confidential regulatory assistance from the Iowa Air Emissions Assistance Program (IAEAP). You may contact IAEAP by phone toll free at 1-800-422-3109, or visit their website at for more information.

+ Prepared Feeds (area sources)

40 CFR Part 63, Subpart DDDDDDD

In September 2014, the Iowa DNR adopted the federal standard for the National Emission Standards for Hazardous Air Pollutants for Prepared Feeds Manufacturing at Area Sources (40 CFR 63 Subpart DDDDDDD), otherwise known as the 7D Rule or 7D NESHAP.

The 7D NESHAP applies to a facility that manufactures prepared animal feed or additives for animal feed (sometimes known as a "feed mill"). Affected facilities must comply with specific requirements to minimize dust and emissions from storage, use, or handling of materials containing chromium and manganese.

The Iowa DNR and the Iowa Air Emissions Assistance Program (IAEAP) at the University of Northern Iowa are assisting affected facilities with the 7D NESHAP and related air construction permitting requirements. For questions or to receive compliance assistance, see the resources provided below.

7D Rule Information

permitting instructions and guidance


+ Surface Coating (Auto Body and Miscellaneous) (Area Sources)