Ozone is three molecules of Oxygen. So in a sense, O3 is O3 no matter where it is. But Ozone is supposed to be in the upper atmosphere around the earth. It is not supposed to be at the ground level – and it’s especially not supposed to be breathed in. One way to think of it is “Good Up High but Bad Nearby”. Ozone in the upper atmosphere is a beneficial and protective layer around the earth, but at ground-level it is harmful air pollution that threatens our health, quality of life, and the Tulsa area’s economic prosperity. Ground-level ozone is created when sunlight reacts with volatile organic compounds (VOCs) and nitrogen oxides (NOX). Reducing these emissions is necessary to reduce ground-level ozone formation.