Main Page | See live article | Alphabetical index Peroxyacetyl nitrate, or PAN for shorthand, is an organic compound consisting of oxygen, and nitrogen as well as a short hydrocarbon chain. It is a principle secondary pollutant in photochemical smog. PAN is both toxic and irritating. At very low concentrations of only a few parts per billion it causes eye irritation. Plants are very sensitive: a fraction of 1ppm causes extensive damage to vegetation. The formula for one such example of PAN is CH3-COO-O-NO2, and consists of a hydrocarbon, nitrogen dioxide, ester and ether group. The formula could be written as C2HO4N. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.