What is NOx and why is it called a pollutant?
NOx is an abbreviation or acronym used to refer to nitric oxide (NO) and nitrogen dioxide (NO2). Both of these chemical compounds contribute to urban smog and can contribute to acid rain so their emissions are carefully controlled by government agencies. They can be formed during high temperature combustion from nitrogen in the air. Careful control of the combustion process or treatment of exhaust gases is needed to keep emissions low.
