An ammonium nitrate explosion produces massive amounts of nitrogen oxides. Nitrogen dioxide (NO₂) is a red, bad-smelling gas. Images from Beirut reveal a distinct reddish colour to the plume of ...

Ammonium nitrate, the material that appears to have ... releasing clouds of yellow-orange smoke. The color is indicative of nitrogen dioxide, also seen in the cloud that appeared seconds before ...

The Los Angeles region has some of the most polluted air in the United States, failing to meet standards set by the Environmental Protection Agency for the last decade. Now, Caltech researchers have ...