Reciprocating Internal Combustion Engines (RICE)

National Emissions Standards for Hazardous Air Pollutants (NESHAP):


The U.S. Environmental Protection Agency finalized standards that place requirements on the owners/operators as well as the manufacturers of stationary reciprocating internal combustion engines to minimize the release of hazardous air pollutants (HAPs). The federal standard, referred to as the National Emissions Standard for Hazardous Air Pollutants (NESHAP), Subpart ZZZZ is complex since there are many previously unregulated smaller engines, including those designated for emergency use, that are now subject to federal regulations.

There are three federal standards regulating the emissions from stationary RICE. These three standards are:

  • NESHAP Subpart ZZZZ (also known as a MACT)
  • NSPS IIII (New Source Performance Standard for stationary compression ignition internal combustion engines)
  • NSPS JJJJ (New Source Performance Standard for stationary spark ignition internal combustion engines)

It is important for the owners and operators of RICE of all sizes, engine types, and fuel types, as well as those considering the purchase of new or reconstructed engines, to understand the requirements for demonstrating compliance with the federal standard(s).animated picture of combustion engine

These documents are designed to help the owners/operators and manufacturers of stationary reciprocating internal combustion engines understand the new federal NESHAP Subpart ZZZZ requirements that reduce emissions released from the engines. Questions regarding the content of these publications may be directed to Anita Singh, Michigan Department of Environmental Quality's Office of Environmental Assistance at (517) 284-6877 or

Compression Ignition Engines: NESHAP Subpart ZZZZ
  - April 2011

Spark Ignition Engines: NESHAP Subpart ZZZZ
  - July 2011


Compression Ignition: