Ground-level ozone (sometimes called smog) is formed from automobile, industrial and other pollutants by chemical reactions when there is bright sunshine with high temperatures. The highest ozone concentrations usually occur between 2 p.m. and 8 p.m. from May through September.

The Ozone Action Partnership is a group of businesses and organizations that take voluntary steps to help reduce the pollution that forms ozone. NJDEP declares Ozone Action Days when we're forecasting exceptionally high concentrations of ground-level ozone. Then the Partnership's participating businesses notify their employees so they can telecommute, share rides to work, use mass transit, and take other steps to help reduce smog. We also notify the press so the public can pitch in too.

Ground-level ozone can lower your resistance to diseases such as colds and pneumonia. It can also damage lung tissue, intensify heart and lung diseases (such as asthma), and cause coughing and throat irritation. Even healthy adults doing heavy exercise or manual labor outdoors may experience the unhealthy effects of ozone. Other people that are sensitive to ozone include the very young and those with pre-existing breathing problems. When ozone reaches unhealthy levels, children and people with asthma are most at risk.

Use the chart at the right to guide how you plan your driving and outdoor activities during the ozone season.