EPA address the emissions of internal combustion engines via both the National Emission Standards for Hazardous Air Pollutants (NESHAP) and the New Source Performance Standards (NSPS). The specific requirement differ depending on whether the engine is new or existing, whether the engine is located at an area source or major source, the installation or reconstruction date, the engine type (compression versus spark ignition), and finally engine size.
There are currently three regulations that apply to stationary engines:
- 40 CFR 63 Subpart ZZZZ: National Emission Standard for Hazardous Air Pollutants (NESHAP) for Reciprocating Internal Combustion Engines (RICE)
- 40 CFR 60 Subpart JJJJ: New Source Performance Standards (NSPS) for Stationary Spark Ignition Internal Combustion Engines
- 40 CFR 60 Subpart IIII: New Source Performance Standards (NSPS) for Stationary Compression Ignition Internal Combustion Engines
Some exemptions to the rules are provided for certain motor vehicles or to non-road engines that are self-propelled (tractors, bulldozers), propelled while performing their function (lawnmowers), and some existing emergency engines.
A navigation tool that may provide some assistance is provided below.