Exemptions from the National Emissions Standards for Hazardous Air Pollutants: What’s the Verdict on Sources in Our Region
- Group Against Smog & Pollution
- May 5
- 7 min read

We blogged last month about an invitation that the U.S. Environmental Protection Agency (EPA) made to sources of hazardous air pollutants (or HAPS) to apply for Presidential exemptions from certain National Emissions Standards for Hazardous Air Pollutants (or NESHAPs), as well as the exemption that the President granted to six coal-fired electric generating units from a 2024 NESHAPs that applies to them.
How is that possible? To review, section 112(i)(4) of the Clean Air Act gives the President the power to exempt a source from the requirements of a NESHAPs if two conditions are met:
“the technology to implement [the NESHAPs] is not available;” and
“it is in the national security interest of the United States” to grant the requested exemption.
The President has already granted NESHAPs exemptions to all the coal-fired electric generating units that asked for them, including six in western Pennsylvania.
“And he did so in a wholly conclusory manner – the Executive Order that granted the exemptions to “America’s beautiful clean coal industry” did not explain why the technology to implement the NESHAPs was unavailable or how national security would be impacted were any one coal-fired electrical generating unit required to implement those controls,” GASP senior staff attorney John Baillie explained.
In light of all this, we wanted to take a look at the other facilities in our region that requested exemptions to get a sense of whether those exemptions should be granted.
“Or perhaps more to the point, whether the exemptions that the President ultimately doles out rest on good grounds and will thus be able to withstand a legal challenge if one is brought,” Baillie said.
As we go through our analysis, let’s assume that the President will contrive reasons to find that it is in the interest of national security to grant the request of the sources that applied for them, as he did with the requests made by coal-fired electric generating units.
And given that assumption, keep in mind that we should expect courts to defer to the President’s determinations regarding national security – judges are experts in the law, not national defense. Generally speaking, what the President says goes in such matters.
Accordingly, we’ll assume that the President will deem every exemption request to meet section 112(i)(4)’s national security prong and focus instead on the second prong – the availability of the control technologies that are needed to comply with the revised NESHAPs – as we look at the remaining requests and offer our verdicts on whether exemptions that the President grants would survive a legal challenge.
What’s the verdict likely to be for the other local sources’ requests to be exempted from the requirements of the revised NESHAPs that apply to them?
Let’s take a look:
American Contract Systems and Cosmed Group Inc.: NESHAPs for Facilities that Use Ethylene Oxide to Sterilize Medical Devices or Equipment
American Contract Systems (ACS) of Zelienople and Cosmed Group Inc.of Erie are facilities that use ethylene oxide (EtO) to sterilize medical devices.
We blogged about the efforts by these sources to come into compliance with the Ethylene Oxide Emission Standards for Sterilization Facilities (or EtO NESHAPs for short) when that standard was first promulgated in April 2024.
Both ACS and Cosmed have requested exemptions from that standard. But both sources would seem to fail section 112(i)(4)’s first prong: We know the control technology to implement the EtO NESHAPs is available to them because they already have that control technology installed and implemented – see this and this (under the heading Additional Details).
Accordingly, even if American Contract Systems, Cosmed Group, or the President can contrive a national security interest that would support granting one or both of them an exemption (who knows, maybe the medical devices they sterilize are used by the military, or could not be obtained from abroad if there were a war), the exemption would not seem to satisfy section 112(i)(4)’s requirement that the control technology needed to comply with the EtO NESHAPs is not available.
THE VERDICT: Any exemptions for these sources should not survive a legal challenge.
U.S. Steel’s Mon Valley Works: NESHAPs for Integrated Iron and Steel Manufacturing Facilities
The only remaining integrated iron and steel manufacturing facility in our region, U.S. Steel’s Mon Valley Works, applied for an exemption from the 2024 revisions to the NESHAPs for such facilities.
The 2024 revisions to the NESHAPs for integrated iron and steel manufacturing facilities added a number of new emission limits and operating requirements:
New or revised limits for the HAPs polycyclic organic compounds, dioxins and furans, carbonyl sulfide, CS2, mercury, hydrochloric acid, and hydrogen fluoride in sinter plants’ emissions;
New opacity limits for emissions from planned and unplanned bleeder valve openings, slag pits, beaching, and bell leaks, as well as new work practice standards for those sources;
New emission limits for the HAPs total hydrocarbons, hydrochloric acid, and dioxins and furans in emissions from blast furnace stoves and basic oxygen process furnaces, as well as new work practice requirements for basic oxygen process furnace shops;
New limits for the HAPs total hydrocarbons and hydrochloric acid in blast furnaces’ emissions; and
A fence line monitoring requirement for chromium.
For the purpose of this analysis, the most interesting new NESHAPs requirements are the first, third, and fourth ones: The new limits for emissions of certain HAPs.
EPA is imposing these limits because in 2020 a federal Court of Appeals determined that section 112(d)(6) of the Act requires EPA to set limits for all HAPs listed by EPA under section 112 of the Clean Air Act that are emitted by facilities subject to a particular NESHAPs when it revises that NESHAPs, not just the ones that the original NESHAPs regulated.
Although iron and steel manufacturing facilities are known to emit the HAPs subject to these new limits, the HAPs were not regulated by the original NESHAPs for the iron and steel manufacturing source category.
Consequently, not a lot of data about those emissions exists.
Thus, it seems that EPA may have based the new emission limits on less data than it would normally have before establishing them. It is also possible that EPA had no emissions data at all from some of the facilities that are subject to the NESHAPs. Indeed, EPA itself “acknowledge[d] that there are uncertainties because of the limited data.”
Due to those uncertainties, it is difficult to say for sure that there is available control technology for the newly regulated HAPs at each iron and steel manufacturing facility subject to the 2024 revisions to the NESHAPs. There very well might be, but it is not certain.
Accordingly, if U.S. Steel’s Mon Valley Works do receive an exemption from the 2024 revisions to the iron and steel NESHAPs, the exemption could conceivably survive a legal challenge. If it does so, it would be on factual grounds relating to the difficulty, expense, or impossibility of controlling the HAPs that were previously unregulated by the NESHAPs.
THE VERDICT: Sorry, the jury’s still out. We’ll have to wait and see how this develops if the President grants an exemption.
U.S. Steel’s Clairton Works and Cleveland Cliffs’ Monessen Coke Plant: NESHAPs for Coke Ovens
Both of the facilities in our region that operate coke ovens (U.S. Steel’s Clairton Works and Cleveland Cliffs’ Monessen Coke Plant) applied for exemptions from the 2024 revisions to the NESHAPs for coke ovens.
The 2024 revisions to the NESHAPs for coke ovens added a number of new standards that apply to byproduct coke ovens like the ones at Clairton and Monessen:
Continuous fence line monitoring for benzene, an action level for benzene, and a duty to determine the root cause of any exceedance of the benzene action level;
Lower limits on the percentage of leaking coke oven doors, lids, and offtake piping;
A new method for estimating emissions from leaking coke oven doors; and
New emission limits for these HAPs: acid gases, dioxins and furans, formaldehyde, hydrogen cyanide, mercury, polycyclic aromatic hydrocarbons (“PAHs”), and volatile organic HAPs.
As was the case with the revised 2024 NESHAPs for iron and steel manufacturing facilities, the most pertinent new NESHAPs requirements for coke ovens are under number four above, the new limits for HAPs that were not regulated by the coke oven NESHAPs before they were revised.
Like the new HAP emission limits in the 2024 revisions to the NESHAPs for iron and steel manufacturing, EPA imposed the new HAP emission limits for coke ovens to satisfy its obligations under section 112(d)(6) of the Clean Air Act.
And like the revised 2024 NESHAPs for iron and steel manufacturing facilities, commenters criticized the new emission limits because those limits were purportedly based on insufficient data. However, unlike with the 2024 revised NESHAPs for iron and steel manufacturing facilities, EPA does not appear to have conceded that there are “uncertainties” in the 2024 revised coke oven NESHAPs due to “limited data.”
An interesting side note about the 2024 revisions to the coke oven NESHAPs: So far as we can tell, the only time that regulated sources claimed that one of the revised NESHAPs for which EPA is offering exemptions impacted national security interests was in comments regarding the coke oven NESHAPs. EPA did not give that claim much credit; it flatly disagreed with the sources’ claim that the 2024 revised NESHAPs would cause coke plants to be shut down.
Nevertheless, what we’re faced with is diametrically opposed claims by industry and EPA regarding the sufficiency of the data that EPA used to promulgate the new HAP emission limits for coke ovens.
We can’t say for sure that the factual record that EPA established regarding the availability of controls needed to comply with the new emission limits in the 2024 revised NESHAPs for coke ovens is so clear that a challenge to an exemption would necessarily hold up if challenged.
It might or might not, depending on the facts put forward.
THE VERDICT: The jury’s also still out here. Again, we’ll have to wait and see how this develops if the President grants exemptions.
Editor’s Note: GASP continues to follow this issue closely. Stay tuned - we will keep you posted.
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