NSR:

New Source Review (The collective name for the Part D NSR and PSD programs.)

ODS:

ozone-depleting substance

OTC:

Ozone Transport Commission

PAL:

plant-wide applicability limitation (A PAL limits emissions from a source or facility as a whole.)

Part D NSR:

This is the NSR program that applies to sources seeking permits in areas whose air quality violate the NAAQS.

PCP:

pollution control project

PM:

particulate matter

PM_2.5:

particles less than 2.5 µm in aerodynamic diameter, called fine particles

PM₁₀:

particles less than 10 µm in aerodynamic diameter

ppm:

parts per million

PSD:

prevention of significant deterioration (This is the NSR program that applies to sources seeking permits in areas whose air quality complies with the NAAQS.)

R&D:

research and development

REMSAD:

Regulatory Modeling System for Aerosols and Acid Deposition

SCR:

selective catalytic reduction

SIC:

Standard Industrial Classification

SIP:

state implementation plan (Every state must prepare a plan to show how it will attain and maintain the NAAQS.)

SNCR:

selective noncatalytic reduction

SO₂:

sulfur dioxide

TVA:

Tennessee Valley Authority

UAM:

Urban Airshed Model

VOC:

volatile organic compound