The 2015 Inventory of Air Emissions released today shows the Port of Los Angeles has largely continued to preserve clean air gains. The 2015 Inventory of Air Emissions released today shows the Port of Los Angeles has largely continued to preserve clean air gains.
PSI Definition: PSI is a unit of pressure expressed in pounds of force per square inch of area. It stands for Pounds per Square Inch. 1 PSI = 6894 Pascals = 0.070 atmospheres = 51.715 torr. Up Next. Up Next.
For air pollution indices in general, see Air quality index. The Pollutant Standards Index, or PSI, is a type of air quality index, which is a number used to provide the public with an easily understandable indicator of how polluted the air is. Initially PSI was based on five air pollutants, but since 1 April 2014 it has also included fine particulate matter (PM 2.5).