Emmissions Standards for Boilers and Process Heaters

The U.S. Environmental Protection Agency (EPA) has finalized the Boiler Maximum Achievable Control Technology (MACT) Rule. The rule is intended to control emissions of hazardous air pollutants (HAPs) from industrial, commercial, and institutional boilers and process heaters. Existing sources that are affected by this rule must comply with the new regulation no later than three years following the date of publication in the Federal Register, which is expected soon.

The Boiler MACT rule contains standards that consist of emission limits, work practice standards, and operating limits that apply to affected sources. It also contains testing, monitoring, recordkeeping, and reporting equirements that are intended to validate initial and ongoing compliance with the standards. In some cases, new or reconstructed sources may have different standards and/or compliance provisions than existing sources. This regulatory update focuses on how the new rule will affect existing sources, and how these sources can effectively plan for compliance. Each affected facility is encouraged to read the regulation and consult a professional before starting the compliance planning process.

On May 16, 2011
, the Environmental Protection Agency again changed course with the Boiler MACT rules, issuing an indefinite stay. As its official notice states:
The effective dates of the final rules published in the Federal Register on March 21, 2011 (76 FR 15608 and 76 FR 15704), are delayed until such time as judicial review is no longer pending or until the EPA completes its reconsideration of the rules, whichever is earlier.


The Boiler MACT regulations can be found in the Code of Federal Regulations at 40 CFR Part 63, Subpart DDDDD. A copy of the rule can be downloaded from the EPA’s Air Toxics website at



The Utility MACT regulations that relate to Power Plants can be downloaded from the EPA’s Air Toxics website at


U.S. Environmental Protection Agency (EPA) Emissions Standards for Boilers and Process Heaters and Commercial / Industrial Solid Waste Incinerators at