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  • Writer's pictureTom Petersen

Hazardous Air Pollutant Regulations for Boilers and Process Heaters

Updated: Aug 28, 2023

National Emission Standards for Hazardous Air Pollutants: Industrial, Commercial, and Institutional Boilers and Process Heaters

40 CFR Part 63, Subpart DDDDD Effective Date: September 13, 2004 Compliance Date: September 13, 2007

This new regulation (known as The Boilers NESHAP) requires maximum achievable control technology (MACT) for Industrial, Commercial, and Institutional Boilers and Process Heaters.

The Boilers NESHAP affects a wide range of industries due to the varied applications of the machinery under regulation. Boilers or process heaters constructed or reconstructed after the proposal date of January 13, 2003 must meet the most stringent requirements. The age of the boiler, the size of the boiler (large, small, or limited use), the fuel it burns (solid, liquid, or gas) and any current methods of emission reduction used (wet scrubbers, fabric filters, etc.) determine which requirements are applicable.

The Boiler NESHAP is applicable to major sources of hazardous air pollutants (HAPs), defined as having the potential to emit at least 10 tons per year of any HAP, or 25 tons per year of a combination of HAPs. Emissions from the entire facility, including non-boiler or process heater sources, count toward major source status.

The regulation includes emission limits for particulate matter, total selected metals (as a surrogate for metallic HAPs such as arsenic, beryllium, cadmium, chromium, lead, manganese, nickel and selenium), hydrogen chloride, mercury and carbon monoxide.

Machinery that must comply with the new regulations falls within one of the following definitions:

Boiler: an enclosed device using controlled flame combustion and that primarily recovers thermal energy in the form of steam or hot water.

Process heater: an enclosed device using a controlled flame that is primarily used to transfer heat indirectly to a process material.

Further information on The Boiler NESHAP may be obtained at

Hazardous Waste Reminders

If an EPA, PADEP, NJDEP, or DNREC RCRA Inspector shows up at your door tomorrow, are you ready? All of these agencies read from the same book, but they may have entirely different interpretations of the rules. Are you aware of your generator status? Have you identified all of your affected employees and their annual training requirements? Do you perform weekly inspections of your hazardous waste satellite and central accumulation areas? How do you know if a waste should be classified as hazardous, universal, residual, or municipal waste? How long can you accumulate these wastes? What kind of treatment is exempt from RCRA? What about DOT and OSHA-mandated training related to hazardous waste? Have you done the contingency planning required by RCRA? Read on for further details…

The US EPA has specific rules that regulate the handling and disposal of hazardous waste. If you treat or store hazardous waste, you have additional requirements, which may include operator certification and permitting. EES can help you navigate through these requirements by conducting a comprehensive training program or a site survey. For more information check out the following link

Closely following the EPA standards are the PA DEP standards. Follow this link to learn more.

For those of you working in Delaware.

Contact Tom Petersen of EES at (215) 704-1506 or

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