OZONE PRECURSOR CATEGORIES
 

Stationary Point Sources: 


 

Stationary source emissions are those air pollutants emitted from identified utility, industrial, institutional and commercial facilities operating at fixed locations.

 

Stationary Area Sources: 




 

Area source emissions are those air pollutants emitted from many individually small activities such as gasoline service stations, small paint shops, and consumer use of solvents.  Area sources also include open burning associated with agriculture, forest management, and land clearing activities.  

 

On-Road Mobile Sources:


 

On-road mobile source emissions are those air pollutants emitted from highway vehicles including cars and light trucks, heavy trucks, buses, engines, and motorcycles.

 

Non-Road Mobile Sources:




 

Non-Road mobile source emissions are those air pollutants emitted from non-road engines including aircraft, locomotives, diesel and gasoline boats and ships, personal water craft, lawn and garden equipment, agricultural and construction equipment, and recreational vehicles (e.g., dirt bikes). 

 

Biogenic Sources:





 

Biogenic source emissions are defined as all pollutants emitted from non-anthropogenic sources. Example sources include trees and vegetation, oil and gas seeps, and microbial activity. While fermentation produces biogenic emissions, gases from this process are included under either point or area sources.